Skip to main content

Spectrum of variants associated with inherited retinal dystrophies in Northeast Mexico

Abstract

Background

Inherited retinal dystrophies are hereditary diseases which have in common the progressive degeneration of photoreceptors. They are a group of diseases with clinical, genetic, and allelic heterogeneity. There is limited information regarding the genetic landscape of inherited retinal diseases in Mexico, therefore, the present study was conducted in the northeast region of the country.

Methods

Patients with inherited retinal dystrophies were included. A complete history, full ophthalmological and medical genetics evaluations, and genetic analysis through a targeted NGS panel for inherited retinal dystrophies comprising at least 293 genes were undertaken.

Results

A total of 126 patients were included. Cases were solved in 74.6% of the study’s population. Retinitis pigmentosa accounted for the most found inherited retinal disease. Ninety-nine causal variants were found, being USH2A and ABCA4 the most affected genes (26 and 15 cases, respectively).

Conclusions

The present study documents the most prevalent causative genes in IRDs, as USH2A, in northeastern Mexico. This contrasts with previous reports of IRDs in other zones of the country. Further studies, targeting previously unstudied populations in Mexico are important to document the genetic background of inherited retinal dystrophies in the country.

Peer Review reports

Introduction

Inherited retinal dystrophies (IRDs) are characterized by progressive degeneration of photoreceptors, resulting in vision loss that may develop from birth to late middle age [1]. IRDs comprise a variety of overlapping conditions, including retinitis pigmentosa (RP), Stargardt disease/macular dystrophy (STGD/MD), cone-rod dystrophies (CRD), Leber congenital amaurosis (LCA) and syndromic forms such as Usher syndrome. Collectively, they have a prevalence of ~ 1 in 2,000–3,000 people [2, 3] and are estimated to affect up to 5.5 million individuals worldwide [4]. Rod dominant dystrophies, such as RP, present with peripheral vision loss and night blindness [5]. By contrast, cone dominant dystrophies, such as STGD/MD and CRD, present with central vision loss and impaired color perception, photophobia, and nystagmus [5, 6]. As both types of dystrophies progress, rod and cones may undergo degeneration compromising both central and peripheral vision at end stages. LCA is the most severe type of IRD, affecting both photoreceptors and the retinal pigment epithelium, with symptoms appearing during the first year of life [6].

IRDs exhibit both genetic and clinical heterogeneity. All inheritance patterns have been reported among IRDs, including autosomal, X-linked, mitochondrial, or digenic patterns [7, 8]. Currently, more than 200 causative genes have been identified, with the majority being autosomal recessive conditions [7, 8]. IRDs show considerable genetic and allelic heterogeneity [2, 3]. For example, ABCA4 mutations have been associated with the development of STGD, RP, CRD, and age-related macular degeneration [9]. Furthermore, intrafamilial variability is common among RDs [10, 11] and it is partly explained by environmental or genetic modifiers, specifically, mutations in other IRDs genes or single nucleotide variants [3].

Identification of the causative genetic variants is essential to ensure an accurate diagnosis and to provide a reference for genetic counseling [8]. In addition, understanding the molecular mechanism of IRDs is leading to the development of therapeutic interventions that seek to halt the loss of photoreceptors and vision preservation [3, 12]. Several studies have employed next-generation sequencing (NGS) techniques in multiple cohorts of RDs patients, with detection rates of molecular defects in ~ 60% of cases [6, 7]. The overall detection rate is not as high as expected for several reasons, including, but not limited to, variants in intronic sequences, uncharacterized genes, variants affecting mRNA splicing, and structural variants, such as copy number variations, duplications, or inversions [5, 7, 8]. There is a large variability of genes and mutations causing IRDs among different populations, and molecular analysis of understudied groups will allow for the reclassification of variants of unknown significance into pathogenic variants [4, 7]. Currently, there is limited data on the underlying genetic variants in families of Mexican descent. Furthermore, the available research has focused on IRDs patients from central and south Mexico [13, 14]. Therefore, the present study was undertaken to contribute to this growing area of research by analyzing the mutation spectrum of IRDs-associated genes in Northeastern Mexican patients, i.e., the states of Coahuila, Nuevo Leon, and Tamaulipas.

Methods

The study protocol was approved by the Institutional Review Board of the School of Medicine at Tecnologico de Monterrey (code P000625-DIMDRET-CEIC-CR001), and all procedures were conducted in compliance with the Declaration of Helsinki. Written informed consent was obtained from all the patients or their legal guardians.

The study population comprised 126 unrelated patients who were selected based on: (1) IRD diagnosis, (2) origin/residence in Northeastern Mexico (Coahuila, Nuevo Leon, and Tamaulipas), and (3) grandparents born in Mexico. Participants were recruited in the following outpatient clinics: Fundación Santos y de la Garza Evia, Fundación Destellos de Luz, Instituto de la Visión of Hospital La Carlota, and from the private practice. IRD diagnosis was based on clinical examination, including uncorrected and corrected visual acuity, fundus examination, visual field testing, fundus autofluorescence, and spectral-domain optical coherence tomography scan. Full-field electroretinography was performed when available. A clinical geneticist collected demographic and familiar data, including family pedigree, age of onset of symptoms, and presence of systemic findings.

DNA sample was extracted from saliva or buccal swab and analyzed with a targeted NGS panel for inherited retinal dystrophies comprising at least 293 genes at Invitae Corp. (San Francisco, CA). Targeted regions were enriched using a hybridization-based protocol and sequenced using Illumina technology. Exon deletions and duplications were assessed using an internal algorithm that compared read-depth for each target sequence in the proband to internal control samples. Classification of variants was based on the American College of Medical Genetics and Genomics (ACMG) guidelines.

Results

Genetic testing was performed on a total of 126 probands with 74 females and 52 males. Probands were natives/residents of Nuevo Leon (94), Tamaulipas (20) and Coahuila (12). The average age of the probands at the time of testing was 39.06 ± 18.64 years (range 4–82 years). The median age at symptoms onset was 13 years (IQ range 17.5) (range 2 months to 70 years). The full demographic and clinical data of the patients is shown in Supplementary material Table 1.

The initial diagnoses in this cohort, according to clinical presentation and examination (Table 2), were: Non-syndromic IRD: RP (53 cases), STGD/MD (21 cases), CRD (15 cases), LCA (3 cases), X-linked retinoschisis (4 cases). Syndromic IRD: Usher 2A syndrome (25 cases), Bardet Biedl syndrome (2 cases), Alstrom syndrome (1 case), 1 case with intellectual disability, short stature, deafness, optic atrophy, and RP, and 1 case with intellectual disability, deafness, coarse facies, and late onset RP.

Cases were classified as solved, partially solved, and unsolved according to a previous work [13] (Table 1). The causative variant detection rate (solved cases) in this cohort was 74.6% (94/126) (Table 2). Partially solved cases were detected in 10/126. A total of 22/126 cases remained unsolved.

Table 1 Case classification
Table 2 Comparison of the three available cohorts from IRDs sequencing in Mexico

Molecular findings / genetic profile of IRD patients

Total different causative variants were 99 among 37 genes, including 96 single nucleotide variants (SNVs) and 3 copy number variations (CNVs), with a total of 175 alleles (Table 3). According to the ACMG guidelines 82 variants were pathogenic, 9 variants were likely pathogenic, and 8 variants were of uncertain significance (VUS). The phenotype and genotype data of the present study were deposited in the LOVD database v.3.0 [15]. Most of the variants were compound heterozygous (49 cases), followed by homozygous (24 cases), heterozygous (13 cases), and hemizygous (8 cases). Most of the variants were determined to be compound heterozygote in 49 cases, followed by homozygous in 24, heterozygous in 13 and hemizygous in 8. DNA changes were predominately missense variants 47, followed by frameshift 16, nonsense 14, splicing 11, intronic 4, CNVs 3, InFrame Indel 2, synonymous 1, start loss 1 (Table 2).

Table 3 Variants found in the present study

Solved cases were classified into non-syndromic IRD 67 and syndromic IRD 27. The most prevalent diagnosis in the non-syndromic solved case was RP, identified in 33 probands, and for syndromic cases was Usher syndrome type 2A found in 21 cases.

There were 58 sporadic cases, the remaining 36 had familial history. Endogamy or consanguinity was documented in 19 and 1 of the cases, respectively. Inheritance pattern was determined as autosomal recessive (AR) in 74 probands, autosomal dominant (AD) in 10 and X-linked (XL) in 10 cases.

The most frequently causative genes in the solved cases were USH2A in 26 and ABCA4 in 15 (Table 2). The remaining affected genes were PROM1 in 5, RPGR in 4, and RS1 in 3, and SAG in 3, which collectively explain over half of the cases. The remaining genes were represented in 32.9% of the solved cases (Fig. 1).

Fig. 1
figure 1

Numbers of cases (in parenthesis) with diagnosed causative genes encountered in the present study

Molecular findings in non-syndromic IRD

RP findings

RP was the most frequent diagnosis in our cohort. A total of 33 probands were characterized by variants identified in at least one of 18 genes. The diagnostic yield /detection rate was 33/53 cases (62.26%). Seven cases were partially solved, but 13 remain unsolved. Inheritance pattern was determined as autosomal recessive in 20 probands, autosomal dominant in 7, X-linked in 6. The most prevalent affected genes were: AR USH2A (6/33), XL RPGR (4/33) and, AD SAG (3/33). Novel variants were 9, identified in 7 genes: CLN3 c.1305C > G (p.Cys435Trp) and c.464 T > G (p.Val155Gly), IFT172 c.4868C > T (p.Thr1623Ile) and c.4876_4878dup (p.Pro1626dup). CEP78 c.473G > T (p.Cys158Phe). CNGA1 c.1065G > C (p.Trp355Cys). EYS c.6079-2A > G (Splice acceptor). SNRNP200 c.2580G > C (p.Gln860His) RPGR Deletion (Exons 8–18). USH2A c.8188C > A (p.Pro2730Thr).

CRD findings

In the group of CRD, 15 cases were evaluated. A total of 9 cases were solved. The diagnostic yield/detection rate was 60%. The most common causative genes were PROM1 and POC1B with 2 cases each. The only inheritance mode was AR. One patient was partially solved and 5 remain unsolved. Two novel variants were identified, one in CFAP410 c.115_117dup (p.Met39dup) and the other in POC1B c.320G > T (p.Ser107Ile).

STGD/MD findings

For STGD/MD, a total of 21 probands were identified with variants distributed among three genes. The diagnostic yield/detection rate was 20/21 (95%). Most of the cases accounted for autosomal recessive STGD (17/21) due to biallelic variants in ABCA4 in 14 cases and 3 cases in PROM1. The remaining 3 cases corresponded to autosomal dominant in two cases (BEST1 and ARL3) and one case with chromosome 1 isodisomy (ABCA4, and USH2A). No novel variants were identified in this group.

XLR and LCA findings

The remaining non-syndromic diagnoses were distributed as follows: XLR (3/4 cases; RS1), LCA (2/3 cases; CEP290, and NMNAT1). The diagnostic yield/detection rates were 75%, 66.7% respectively. A novel CNV variant was identified in CEP290 Gain (Exons 16–26) in a patient with LCA.

Molecular findings in syndromic-IRD

A total of 27/30 cases were solved for this cohort (detection rate:90%), including twenty patients with Usher type 2A syndrome and one Usher type 2C syndrome (ADGRV1). Other syndromic diagnoses in this cohort were Bardet-Biedl syndrome (2 cases; BBS5 and ARL6), Alstrom syndrome (1 case; ALMS1), Mucopolysaccharidosis type IIIC/ Sanfilippo C (1 case; HGSNAT), Arts syndrome (1 case, PRPS1), and Wolfram-like syndrome (1 case; WFS1). Two novel variants were reported for this group, both in HGSNAT: a CNV deletion (Exons 1–2) and a c.185 T > C (p.Leu62Pro) missense variant.

USH2A gene variants

The number of cases associated with USH2A is remarkably abundant in this cohort, because 27 patients had causative variants in this gene. Twenty cases were syndromic, six were non-syndromic RP cases whereas one had CRD diagnosis. USH2A was the most prevalent affected gene for the whole cohort, with a total of 56 alleles, distributed in 14 variants. For the syndromic phenotype the whole number of alleles were 42, distributed in 10 different variants. The total alleles for non-syndromic RP cases were 12, distributed in 5 variants and only 2 variants for the CRD. The diagnostic yield/detection rate for syndromic Usher 2A was 86.9% (20/23). Family history was reported only in 10/20 of the syndromic cases. The most prevalent pathogenic variants detected in syndromic USH2A cases included a frameshift mutation due to c.2299del (p.Glu767Serfs*21) (22/42 alleles; 52.38%), followed by the splicing change c.12067-2A > G (6/42 alleles; 14.28%), and the missense variant c.956G > A (p.Cys319Tyr) (3/42 alleles; 7.14%). The homozygous variants corresponded to 11 patients, seven cases for c.2299del (p.Glu767Serfs*21) and one for each of the follow: c.2276G > T (p.Cys759Phe); c.12067-2A > G; c.486-14G > A (Intronic); c.5278del (p.Asp1760Metfs*10); c.2276G > T (p.Cys759Phe). In the homozygous cases, endogamy or consanguinity was positive in 3/11 and 1/11 was an isodisomy of chromosome 1. For the simplex RP cases, the most prevalent allele was c.2276G > T (p.Cys759Phe (5/12 alleles), only one case with this variant was in homozygous state. The remaining, a CRD case was a compound heterozygote. Consanguinity or endogamy was denied for RP and CRD.

Partially solved cases

A total of 10/126 (7.9%) was classified as partially solved. The prevalence of the pathogenic or probably pathogenic variants were distributed in heterozygous state as follows: USH2A 4/10, KIZ 2/10, ABCA4 1/10, MFRP 1/10, CRB1 1/10, CLN5 1/10. None of these variants were novel.

Suspected causal VUS and unsolved cases

In this cohort, 17.46% (22/126) cases remain unsolved, their clinical diagnoses were 13 RP, 5 CRD, 1 LCA, 1 BD, 1 XLR, 1 Usher syndrome. Unclassified genotypes were due to the identification of only one recessive pathogenic variant without clinical correlation or only VUS. Three of these cases had relevant molecular findings. A 49 years female with nyctalopia since age 3, followed by peripheral vision loss. At 40 years, bone spicules were found, and RP was diagnosed. Two VUS on opposite chromosomes were identified in CNGB1 c.1676C > A (p.Thr559Lys) and c.1720C > T (p.Leu574Phe). Considering her clinical presentation and the possible effects on the protein, these variants could be causal. A second case is a 58 years male, who started with photophobia at 42 years followed by dyschromatopsia. He carries an heterozygous VUS in GUCY2D c.2795 T > G (p.Met932Arg). Considering his clinical phenotype, the mother visual deficiency, and predictions on the effect of this variant on protein structure and function [85], we assume that this variant is likely disruptive. The third case is a 17 years male patient with X-linked retinoschisis. Since he was 6 years he presented central blurry vision. Glasses were prescribed but they did not improve his vision. At 14 years, a retinologist noticed foveal schisis, and asked for optical coherence tomography (OCT) which supported this diagnosis. In his molecular test a VUS in hemizygous state was found in RSI c.341C > T (p.Ser114Phe). These three unsolved cases were isolated cases, the four VUS were novel. The remaining cases didn’t have a clinical correlation with the encountered VUS.

Discussion

Genetic variants for IRDs are present in up to 36% of the world population, when accounting for asymptomatic carriers of recessive mutations [4]. As many of these mutations could be novel in nature and geographically prevalent due to founder effects, the genetic study of IRDs in diverse groups of populations is highly relevant [13]. The enormous genetic and phenotypical heterogeneity of IRDs is reflected in this work. The cohort contains 126 cases, pathogenic or probably pathogenic variants were identified in 94 cases, 10 cases were partially solved cases and 22 persisted as unsolved cases. To the authors’ best knowledge, two previous large cohorts have reported genetic findings in IRDs in patients originating from central and south Mexico [13, 14], so it is important to complete the information for these retinal pathologies in other regions of the country. In addition, it is also important to consider the genetic differences in the northeastern population which could possess a greater proportion of European alleles [86, 87] compared with the central/south Mexican populations.

A similar number of patients were examined across the previous cohorts and the present study (144, 143 and 126 patients respectively) [13, 14]. Regarding gender distribution, while a slight female predilection was found in the present study (56.3 vs 44%), the opposite was reported by Villanueva, et al. [13] (58.3 vs 41.7% of males and females respectively) and no gender distribution was reported by Zenteno, et al. [14]. A comparison of the characteristics of the patients from the three cohorts is shown in Table 2. The most common, pre-sequencing diagnosis was RP across all three cohorts. In addition, the mutation detection rate was similar in all 3 studies, ranging from 70–80% and the most detected mutation type were missense variants across all three studies. On the other hand, the most frequently encountered affected gene in the present study was USH2A (29.78%). This number differs from previous studies on Mexicans, whose reports were 3.5% [13] and 7% [14]. In the other cohorts ABCA4 was more frequently altered [13, 14]. Finally, the proportion of unsolved cases was similar between the present study and Villanueva-Mendoza, et al. [13] (15.3 vs 17.46%) and higher in the cohort from Zenteno, et al. [14] (33.5%). The considerable proportion of unsolved cases could be related to gene panel limitations, including its capability to detect RPGR variants, CNVs, and intronic variants.

The most frequent pathogenic variant of the whole cohort was c.2299del (p.Glu767Serfs*21) in USH2A. This variant is in exon 13 is the subject of a phase 3 therapy clinical trial involving the investigational new drug Ultevursen, an antisense RNA oligonucleotide (NCT05158296). The high prevalence of the c.2299del variant in USH2A found in the present study could be relevant for this therapy if it is approved. There is sufficient clinical evidence that the c.2299del (p.Glu767SerfsTer21) variant is pathogenic and highly prevalent. A recent report on the frequency of this variant in the cases from central and southern Mexico accounts for 7 and 23% of the alleles causing non-syndromic RP and Usher syndrome, respectively [88]. Furthermore, the Genome Aggregation Database v.4.0.0 shows that the frequency of this allele in the admixed Latino population is 0.0014, the highest globally, followed by the 0.001176 frequency in non-Finnish Europeans [89]. Dreyer, et al. reported the c.2299del variant in patients from Europe, North and South America, South Africa, and China and noted that it is associated to a core haplotype suggesting that this mutation is an ancestral mutation spread in Europe and introduced in the Americas after the conquest [90].

Other genetic therapies in development are relevant for this report. The vMCO-010 in phase 2 clinical trial (NCT05417126) and rAAV2tYF-GRK1-RPGR in phase 1/2 clinical trial (NCT03316560) are two promising therapies for patients with STGD/MD and X-Linked RPGR, respectively. On the other hand, no patients with RPE65 variants were found in this cohort, therefore no candidates for the only approved gene therapy for IRDs are reported.

Of all causative variants in this cohort, 14 were novel. Eight of these were missense variants (one pathogenic, five VUS, and two probably pathogenic). Three were CNVs, all classified as pathogenic, two frameshift variants classified as VUS and one splicing classified as probably pathogenic. All VUS are suggested to be disrupting variants but there was not enough evidence to classify them as pathogenic. The three novel CNVs may be explained by the recent developments in NGS detection by NGS suggesting that CNV detection will improve the diagnosis rate.

There were some interesting cases. The first was a case with isodisomy of chromosome 1, which has been already reported [91]. We also detected a patient with type IIIC mucopolysaccharidosis (Sanfilippo C), a 55 years patient, with severe intellectual disability, speech impairment, deafness, coarse facies, motor deterioration and late onset RP. He had an affected sister who suddenly died at 21. This patient has two novel HGSNAT variants, one CNV classified as pathogenic, and one missense classified as VUS. This could be the first case reported in a Mexican patient. Another interesting case was a woman patient with Arts syndrome, an X-linked disorder, who suffers from retinal dystrophy, optical atrophy, deafness, short stature, and intellectual disability. Among the unsolved cases, there is one case with isolated RP and two biallelic variants in CNBG1, c.1676C > A (p.Thr559Lys) and c.1720C > T (p.Leu574Phe), both classified as VUS. Looking into the clinical presentation of this patient and the changes at the protein level, we can conclude that there is a clinical correlation and that those VUS are probably disruptive. Another remarkable case was a 15 years male with juvenile retinoschisis, carrying a VUS in hemizygous state at RS1 identified as c.341C > T (p.Ser114Phe). This variant is highly likely to be the cause of the clinical presentation. Another notable case, was a 58 years male with CRD, with the VUS c.2795 T > G (p.Met932Arg) in heterozygous genotype in GUCY2D. The clinical presentation, the suggestive mother visual symptoms, and the amino acid changes suggest that this variant is highly suspicious of being disruptive as suggested by algorithmic predictions [92].

This study has some limitations, such as the sample size, as there were only 126 patients. Another limitation could be that this panel only encompasses genes in nuclear DNA and very few intronic variants. Sequence changes in the promoter, non-coding exons, and other non-coding regions were not covered. Additionally, no ancestry and founder effect studies were performed.

Conclusions

This study provides more information about the landscape of the mutations in the IRDs patients in Mexico. Contrary to previous studies in other locations in Mexico, USH2A was the most frequently affected gene in the present study. This suggests that there are differences in the genetic component of IRDs between the various regions of the country. It is paramount to study other regions that had not been studied yet, and to create a national registry of IRDs patients. Therapies may arrive soon, or there could be some protocols carried out in Mexico, there, lies the importance of an accurate diagnosis in these patients.

Availability of data and materials

The authors have provided a normal table and a supplementary material with all the genetic and clinical results of the present paper. Additionally, all the data from the present manuscript is available in the database LOVD v.3.0. The specific reference is available in the results section. Further data availability can be asked for by contacting the corresponding author.

Database link:

https://databases.lovd.nl/shared/variants#order=VariantOnGenome%2FDNA%2CASC&search_VariantOnGenome/Reference=Cruz%20RA%2C%20et%20al.%2C%202023&page_size=100&page=1.

References

  1. Rattner A, Sun H, Nathans J. Molecular genetics of human retinal disease. Annu Rev Genet. 1999;33:89–131. https://doi.org/10.1146/annurev.genet.33.1.89.

    Article  CAS  PubMed  Google Scholar 

  2. Merepa SS, Broadgate S, Sekaran S, Halford S. Genetics of the retinal dystrophies. ELS. 2018:1–10. https://doi.org/10.1002/9780470015902.a0028116.

  3. Talib M, Boon CJF. Retinal dystrophies and the road to treatment: clinical requirements and considerations. Asia Pac J Ophthalmol. 2020;9(3):159–79. https://doi.org/10.1097/APO.0000000000000290.

    Article  Google Scholar 

  4. Hanany M, Rivolta C, Sharon D. Worldwide carrier frequency and genetic prevalence of autosomal recessive inherited retinal diseases. Proc Natl Acad Sci USA. 2020;117(5):2710–6. https://doi.org/10.1073/pnas.1913179117.

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  5. Cremers F, Boon C, Bujakowska K, Zeitz C. Special issue introduction: inherited retinal disease: novel candidate genes, genotype–phenotype correlations, and inheritance models. Genes. 2018;9(4):215. https://doi.org/10.3390/genes9040215.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Nash BM, Wright DC, Grigg JR, Bennetts B, Jamieson RV. Retinal dystrophies, genomic applications in diagnosis and prospects for therapy. Transl Pediatr. 2015;4(2):139–963. https://doi.org/10.3978/j.issn.2224-4336.2015.04.

    Article  PubMed  PubMed Central  Google Scholar 

  7. Farrar GJ, Carrigan M, Dockery A, Millington-Ward S, Palfi A, Chadderton N, Humphries M, Kiang AS, Kenna PF, Humphries P. Toward an elucidation of the molecular genetics of inherited retinal degenerations. Hum Mol. 2017;26:R2.

    Article  CAS  Google Scholar 

  8. Garafalo AV, Cideciyan AV, Héon E, Sheplock R, Pearson A, WeiYang Yu C, Sumaroka A, Aguirre GD, Jacobson SG. Progress in treating inherited retinal diseases: Early subretinal gene therapy clinical trials and candidates for future initiatives. Prog Retin Eye Res. 2020;77:100827. https://doi.org/10.1016/j.preteyeres.2019.100827.

  9. Al-khuzaei S, Broadgate S, Foster CR, Shah M, Yu J, Downes SM, Halford S. An overview of the genetics of abca4 retinopathies, an evolving story. Genes. 2021;12(8):1241. https://doi.org/10.3390/genes12081241.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Hull S, Arno G, Plagnol V, Chamney S, Russell-Eggitt I, Thompson D, Ramsden SC, Black GC, Robson AG, Holder GE, Moore AT, Webster AR. The phenotypic variability of retinal dystrophies associated with mutations in CRX, with report of a novel macular dystrophy phenotype. Invest Ophthalmol Vis Sci. 2014;55(10):6934–44. https://doi.org/10.1167/iovs.14-14715.

  11. Leroy BP, Kailasanathan A, De Laey JJ, Black GC, Manson FD. Intrafamilial phenotypic variability in families with RDS mutations: exclusion of ROM1 as a genetic modifier for those with retinitis pigmentosa. Br J Ophthalmol. 2007;91(1):89–93. https://doi.org/10.1136/bjo.2006.101915.

  12. Mustafi D, Arbabi A, Ameri H, Palczewski K. Retinal gene distribution and functionality implicated in inherited retinal degenerations can reveal disease-relevant pathways for pharmacologic intervention. Pharmaceuticals. 2019;12(2):74.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Villanueva-Mendoza C, Tuson M, Apam-Garduño D, de Castro-Miró M, Tonda R, Trotta JR, Marfany G, Valero R, Cortés-González V, Gonzàlez-Duarte R. The Genetic Landscape of Inherited Retinal Diseases in a Mexican Cohort: Genes, Mutations and Phenotypes. Genes (Basel). 2021;12(11):1824. https://doi.org/10.3390/genes12111824.

  14. Zenteno JC, García-Montaño LA, Cruz-Aguilar M, Ronquillo J, Rodas-Serrano A, Aguilar-Castul L, Matsui R, Vencedor-Meraz CI, Arce-González R, Graue-Wiechers F, Gutiérrez-Paz M, Urrea-Victoria T, de Dios Cuadras U, Chacón-Camacho OF. Extensive genic and allelic heterogeneity underlying inherited retinal dystrophies in Mexican patients molecularly analyzed by next-generation sequencing. Mol Genet Genomic Med. 2020;8(1). https://doi.org/10.1002/mgg3.1044 . Epub 2019 Nov 17.

  15. Villafuerte-de la Cruz Rocio A, et al. Spectrum of variants associated with inherited retinal dystrophies in Northeast Mexico database. In: LOVD3 (Leiden open variation database v.3.0). Available: https://databases.lovd.nl/shared/variants#order=VariantOnGenome%2FDNA%2CASC&search_VariantOnGenome/Reference=Cruz%20RA%2C%20et%20al.%2C%202023&page_size=100&page=1. Accessed 10.04.2023.

  16. Zeitz C, Robson AG, Audo I. Congenital stationary night blindness: ananalysis and update of genotype-phenotype correlations and pathogenicmechanisms. Prog Retin Eye Res. 2015;45:58–110. https://doi.org/10.1016/j.preteyeres.2014.09.001. Epub 2014 Oct 13.

    Article  PubMed  Google Scholar 

  17. Santorelli FM, Garavaglia B, Cardona F, Nardocci N, Bernardina BD, Sartori S, Suppiej A, Bertini E, Claps D, Battini R, Biancheri R, Filocamo M, Pezzini F, Simonati A. Molecular epidemiology of childhood neuronalceroid-lipofuscinosis in Italy. Orphanet J Rare Dis. 2013;2(8):19. https://doi.org/10.1186/1750-1172-8-19.

    Article  Google Scholar 

  18. Kuper WFE, van Alfen C, van Eck L, de Man SA, Willemsen MH, van Gassen KLI, Losekoot M, van Hasselt PM. The c.1A > C start codon mutation in CLN3 is associated with a protracted disease course. JIMD Rep. 2020;52(1):23–7. https://doi.org/10.1002/jmd2.12097.

  19. Koyanagi Y, Akiyama M, Nishiguchi KM, Momozawa Y, Kamatani Y, Takata S, Inai C, Iwasaki Y, Kumano M, Murakami Y, Omodaka K, Abe T, Komori S, Gao D, Hirakata T, Kurata K, Hosono K, Ueno S, Hotta Y, Murakami A, … Sonoda KH. Genetic characteristics of retinitis pigmentosa in 1204 Japanese patients. J Med Genet. 2019;56(10):662–70. https://doi.org/10.1136/jmedgenet-2018-105691.

  20. Baralle D, Baralle M. Splicing in action: assessing disease causing sequence changes. J Med Genet. 2005;42(10):737–48. https://doi.org/10.1136/jmg.2004.029538.

  21. Hull S, Attanasio M, Arno G, Carss K, Robson AG, Thompson DA, Plagnol V, Michaelides M, Holder GE, Henderson RH, Raymond FL, Moore AT, Webster AR. Clinical Characterization ofCNGB1-Related Autosomal Recessive Retinitis Pigmentosa. JAMA Ophthalmol. 2017;135(2):137–44. https://doi.org/10.1001/jamaophthalmol.2016.5213.

    Article  PubMed  Google Scholar 

  22. den Hollander AI, Heckenlively JR, van den Born LI, de Kok YJ, van der Velde-Visser SD, Kellner U, Jurklies B, van Schooneveld MJ, Blankenagel A, Rohrschneider K, Wissinger B, Cruysberg JR, Deutman AF, Brunner HG, Apfelstedt-Sylla E, Hoyng CB, Cremers FP. Leber congenital amaurosis and retinitis pigmentosa with Coats-like exudative vasculopathy are associated with mutations in the crumbs homologue 1 (CRB1) gene. Am J Hum Genet. 2001;69(1):198–203. https://doi.org/10.1086/321263.

  23. Bujakowska K, Audo I, Mohand-Saïd S, Lancelot ME, Antonio A, Germain A, Léveillard T, Letexier M, Saraiva JP, Lonjou C, Carpentier W, Sahel JA, Bhattacharya SS, Zeitz C. CRB1 mutations in inherited retinal dystrophies. Hum Mutat. 2012;33(2):306–15. https://doi.org/10.1002/humu.21653.

    Article  CAS  PubMed  Google Scholar 

  24. Sengillo JD, Lee W, Nagasaki T, Schuerch K, Yannuzzi LA, Freund KB, Sparrow JR, Allikmets R, Tsang SH. A Distinct Phenotype of Eyes Shut Homolog (EYS)-Retinitis Pigmentosa Is Associated With Variants Near the C-Terminus. Am J Ophthalmol. 2018;190:99–112. https://doi.org/10.1016/j.ajo.2018.03.008. Epub 2018 Mar 14.

    Article  PubMed  PubMed Central  Google Scholar 

  25. Audo I, Sahel JA, Mohand-Saïd S, Lancelot ME, Antonio A, Moskova-Doumanova V, Nandrot EF, Doumanov J, Barragan I, Antinolo G, Bhattacharya SS, Zeitz C. EYS is a major gene for rod-cone dystrophies in France. Hum Mutat. 2010;31(5):E1406–35. https://doi.org/10.1002/humu.21249.

    Article  CAS  PubMed  Google Scholar 

  26. El Shamieh S, Neuillé M, Terray A, Orhan E, Condroyer C, Démontant V, Michiels C, Antonio A, Boyard F, Lancelot ME, Letexier M, Saraiva JP, Léveillard T, Mohand-Saïd S, Goureau O, Sahel JA, Zeitz C, Audo I. Whole-exome sequencing identifies KIZ as a ciliary gene associated with autosomal-recessive rod-cone dystrophy. Am J Hum Genet. 2014;94(4):625–33. https://doi.org/10.1016/j.ajhg.2014.03.005.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Ávila-Fernández A, Cantalapiedra D, Aller E, Vallespín E, Aguirre-Lambán J, Blanco-Kelly F, Corton M, Riveiro-Álvarez R, Allikmets R, Trujillo-Tiebas MJ, Millán JM, Cremers FP, Ayuso C. Mutation analysis of 272 Spanish families affected by autosomal recessive retinitis pigmentosa using a genotyping microarray. Mol Vis. 2010;16:2550–8.

    PubMed  PubMed Central  Google Scholar 

  28. Siemiatkowska AM, Arimadyo K, Moruz LM, Astuti GD, de Castro-Miro M, Zonneveld MN, Strom TM, de Wijs IJ, Hoefsloot LH, Faradz SM, Cremers FP, den Hollander AI, Collin RW. Molecular genetic analysis of retinitis pigmentosa in Indonesia using genome-wide homozygosity mapping. Mol Vis. 2011;17:3013–24.

    CAS  PubMed  PubMed Central  Google Scholar 

  29. Corton M, Blanco MJ, Torres M, Sanchez-Salorio M, Carracedo A, Brion M. Identification of a novel mutation in the human PDE6A gene in autosomal recessive retinitis pigmentosa: homology with the nmf28/nmf28 mice model. Clin Genet. 2010;78(5):495–8. https://doi.org/10.1111/j.1399-0004.2010.01487.x.

    Article  CAS  PubMed  Google Scholar 

  30. Rivolta C, Sweklo EA, Berson EL, Dryja TP. Missense mutation in the USH2A gene: association with recessive retinitis pigmentosa without hearing loss. Am J Hum Genet. 2000;66(6):1975–8. https://doi.org/10.1086/302926.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Weston MD, Eudy JD, Fujita S, Yao S, Usami S, Cremers C, Greenberg J, Ramesar R, Martini A, Moller C, Smith RJ, Sumegi J, Kimberling WJ. Genomic structure and identification of novel mutations in usherin, the gene responsible for Usher syndrome type IIa. Am J Hum Genet. 2000;66(4):1199–210. https://doi.org/10.1086/302855.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Villanueva A, Biswas P, Kishaba K, Suk J, Tadimeti K, Raghavendra PB, Nadeau K, Lamontagne B, Busque L, Geoffroy S, Mongrain I, Asselin G, Provost S, Dubé MP, Nudleman E, Ayyagari R. Identification of the genetic determinants responsible for retinal degeneration in families of Mexican descent. Ophthalmic Genet. 2018;39(1):73–9. https://doi.org/10.1080/13816810.2017.1373830.

    Article  CAS  PubMed  Google Scholar 

  33. McGee TL, Seyedahmadi BJ, Sweeney MO, Dryja TP, Berson EL. Novel mutations in the long isoform of the USH2A gene in patients with Usher syndrome type II or non-syndromic retinitis pigmentosa. J Med Genet. 2010;47(7):499–506. https://doi.org/10.1136/jmg.2009.075143.

    Article  CAS  PubMed  Google Scholar 

  34. Sullivan LS, Bowne SJ, Birch DG, Hughbanks-Wheaton D, Heckenlively JR, Lewis RA, Garcia CA, Ruiz RS, Blanton SH, Northrup H, Gire AI, Seaman R, Duzkale H, Spellicy CJ, Zhu J, Shankar SP, Daiger SP. Prevalence of disease-causing mutations in families with autosomal dominant retinitis pigmentosa: a screen of known genes in 200 families. Invest Ophthalmol Vis Sci. 2006;47(7):3052–64. https://doi.org/10.1167/iovs.05-1443.

    Article  PubMed  Google Scholar 

  35. Michaelides M, Holder GE, Bradshaw K, Hunt DM, Moore AT. Cone-rod dystrophy, intrafamilial variability, and incomplete penetrance associated with the R172W mutation in the peripherin/RDS gene. Ophthalmology. 2005;112(9):1592–8. https://doi.org/10.1016/j.ophtha.2005.04.004.

    Article  PubMed  Google Scholar 

  36. Vervoort R, Lennon A, Bird AC, Tulloch B, Axton R, Miano MG, Meindl A, Meitinger T, Ciccodicola A, Wright AF. Mutational hot spot within a new RPGR exon in X-linked retinitis pigmentosa. Nat Genet. 2000;25(4):462–6. https://doi.org/10.1038/78182.

    Article  CAS  PubMed  Google Scholar 

  37. Moore A, Escudier E, Roger G, Tamalet A, Pelosse B, Marlin S, Clément A, Geremek M, Delaisi B, Bridoux AM, Coste A, Witt M, Duriez B, Amselem S. RPGR is mutated in patients with a complex X linked phenotype combining primary ciliary dyskinesia and retinitis pigmentosa. J Med Genet. 2006;43(4):326–33. https://doi.org/10.1136/jmg.2005.034868.

    Article  CAS  PubMed  Google Scholar 

  38. Guevara-Fujita M, Fahrner S, Buraczynska K, Cook J, Wheaton D, Cortes F, Vicencio C, Pena M, Fishman G, Mintz-Hittner H, Birch D, Hoffman D, Mears A, Fujita R, Swaroop A. Five novel RPGR mutations in families with X-linked retinitis pigmentosa. Hum Mutat. 2001;17(2):151. https://doi.org/10.1002/1098-1004(200102)17:2<151::AID-HUMU7>3.0.CO;2-W.

    Article  CAS  PubMed  Google Scholar 

  39. Jayasundera T, Branham KE, Othman M, Rhoades WR, Karoukis AJ, Khanna H, Swaroop A, Heckenlively JR. RP2 phenotype and pathogenetic correlations in X-linked retinitis pigmentosa. Arch Ophthalmol. 2010;128(7):915–23. https://doi.org/10.1001/archophthalmol.2010.122.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Buratti E, Chivers M, Královicová J, Romano M, Baralle M, Krainer AR, Vorechovsky I. Aberrant 5’ splice sites in human disease genes: mutation pattern, nucleotide structure and comparison of computational tools that predict their utilization. Nucleic Acids Res. 2007;35(13):4250–63. https://doi.org/10.1093/nar/gkm402.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Wang Z, Iida A, Miyake N, Nishiguchi KM, Fujita K, Nakazawa T, Alswaid A, Albalwi MA, Kim OH, Cho TJ, Lim GY, Isidor B, David A, Rustad CF, Merckoll E, Westvik J, Stattin EL, Grigelioniene G, Kou I, Nakajima M, Ikegawa S. Axial Spondylometaphyseal Dysplasia Is Caused by C21orf2 Mutations. PLoS One. 2016;11(3):e0150555. https://doi.org/10.1371/journal.pone.0150555.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Wissinger B, Gamer D, Jägle H, Giorda R, Marx T, Mayer S, Tippmann S, Broghammer M, Jurklies B, Rosenberg T, Jacobson SG, Sener EC, Tatlipinar S, Hoyng CB, Castellan C, Bitoun P, Andreasson S, Rudolph G, Kellner U, Lorenz B, Kohl S. CNGA3 mutations in hereditary cone photoreceptor disorders. Am J Hum Genet. 2001;69(4):722–37. https://doi.org/10.1086/323613.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Carss KJ, Arno G, Erwood M, Stephens J, Sanchis-Juan A, Hull S, Megy K, Grozeva D, Dewhurst E, Malka S, Plagnol V, Penkett C, Stirrups K, Rizzo R, Wright G, Josifova D, Bitner-Glindzicz M, Scott RH, Clement E, Allen L, …, Raymond FL. Comprehensive Rare Variant Analysis via Whole-Genome Sequencing to Determine the Molecular Pathology of Inherited Retinal Disease. Am J Hum Genet. 2017;100(1):75–90. https://doi.org/10.1016/j.ajhg.2016.12.003.

    Article  CAS  PubMed  Google Scholar 

  44. Mayer AK, Van Cauwenbergh C, Rother C, Baumann B, Reuter P, De Baere E, Wissinger B, Kohl S, ACHM Study Group. CNGB3 mutation spectrum including copy number variations in 552 achromatopsia patients. Hum Mutat. 2017;38(11):1579–91. https://doi.org/10.1002/humu.23311.

  45. Chang B, Grau T, Dangel S, Hurd R, Jurklies B, Sener EC, Andreasson S, Dollfus H, Baumann B, Bolz S, Artemyev N, Kohl S, Heckenlively J, Wissinger B. A homologous genetic basis of the murine cpfl1 mutant and human achromatopsia linked to mutations in the PDE6C gene. Proc Natl Acad Sci U S A. 2009;106(46):19581–6. https://doi.org/10.1073/pnas.0907720106.

    Article  ADS  PubMed  PubMed Central  Google Scholar 

  46. Kominami A, Ueno S, Kominami T, Nakanishi A, Ito Y, Fujinami K, Tsunoda K, Hayashi T, Kikuchi S, Kameya S, Iwata T, Terasaki H. Case of cone dystrophy with normal fundus appearance associated with biallelic POC1B variants. Ophthalmic Genet. 2018;39(2):255–62. https://doi.org/10.1080/13816810.2017.1408846. Epub 2017 Dec 8.

    Article  CAS  PubMed  Google Scholar 

  47. Porto FBO, Jones EM, Branch J, Soens ZT, Maia IM, Sena IFG, Sampaio SAM, Simões RT, Chen R. Molecular Screening of 43 Brazilian Families Diagnosed with Leber Congenital Amaurosis or Early-Onset Severe Retinal Dystrophy. Genes (Basel). 2017;8(12):355. https://doi.org/10.3390/genes8120355.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Zhang Q, Zulfiqar F, Xiao X, Riazuddin SA, Ahmad Z, Caruso R, MacDonald I, Sieving P, Riazuddin S, Hejtmancik JF. Severe retinitis pigmentosa mapped to 4p15 and associated with a novel mutation in the PROM1 gene. Hum Genet. 2007;122(3–4):293–9. https://doi.org/10.1007/s00439-007-0395-2. Epub 2007 Jun 29.

    Article  CAS  PubMed  Google Scholar 

  49. Jespersgaard C, Fang M, Bertelsen M, Dang X, Jensen H, Chen Y, Bech N, Dai L, Rosenberg T, Zhang J, Møller LB, Tümer Z, Brøndum-Nielsen K, Grønskov K. Molecular genetic analysis using targeted NGS analysis of 677 individuals with retinal dystrophy. Sci Rep. 2019;9(1):1219. https://doi.org/10.1038/s41598-018-38007-2.

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  50. Salles MV, Motta FL, Martin R, Filippelli-Silva R, Dias da Silva E, Varela P, Costa KA, Chiang JP, Pesquero JB, Sallum JF. Variants in the ABCA4 gene in a Brazilian population with Stargardt disease. Mol Vis. 2018;24:546–9.

  51. Chacón-Camacho OF, Granillo-Alvarez M, Ayala-Ramírez R, Zenteno JC. ABCA4 mutational spectrum in Mexican patients with Stargardt disease: Identification of 12 novel mutations and evidence of a founder effect for the common p. A1773V mutation. Exp Eye Res. 2013;109:77–82. https://doi.org/10.1016/j.exer.2013.02.006.

    Article  CAS  PubMed  Google Scholar 

  52. Gerber S, Rozet JM, van de Pol TJ, Hoyng CB, Munnich A, Blankenagel A, Kaplan J, Cremers FP. Complete exon-intron structure of the retina-specific ATP binding transporter gene (ABCR) allows the identification of novel mutations underlying Stargardt disease. Genomics. 1998;48(1):139–42. https://doi.org/10.1006/geno.1997.5164.

    Article  CAS  PubMed  Google Scholar 

  53. Wiszniewski W, Zaremba CM, Yatsenko AN, Jamrich M, Wensel TG, Lewis RA, Lupski JR. ABCA4 mutations causing mislocalization are found frequently in patients with severe retinal dystrophies. Hum Mol Genet. 2005;14(19):2769–78. https://doi.org/10.1093/hmg/ddi310.

    Article  CAS  PubMed  Google Scholar 

  54. Wang Y, Sun W, Zhou J, Li X, Jiang Y, Li S, Jia X, Xiao X, Ouyang J, Wang Y, Zhou L, Long Y, Liu M, Li Y, Yi Z, Wang P, Zhang Q. Different Phenotypes Represent Advancing Stages of ABCA4-Associated Retinopathy: A Longitudinal Study of 212 Chinese Families From a Tertiary Center. Invest Ophthalmol Vis Sci. 2022;63(5):28. https://doi.org/10.1167/iovs.63.5.28.

    Article  PubMed  PubMed Central  Google Scholar 

  55. Marinakis NM, Svingou M, Veltra D, Kekou K, Sofocleous C, Tilemis FN, Kosma K, Tsoutsou E, Fryssira H, Traeger-Synodinos J. Phenotype-driven variant filtration strategy in exome sequencing toward a high diagnostic yield and identification of 85 novel variants in 400 patients with rare Mendelian disorders. Am J Med Genet A. 2021;185(8):2561–71. https://doi.org/10.1002/ajmg.a.62338. Epub 2021 May 19.

    Article  CAS  PubMed  Google Scholar 

  56. Del Pozo-Valero M, Riveiro-Alvarez R, Blanco-Kelly F, Aguirre-Lamban J, Martin-Merida I, Iancu IF, Swafiri S, Lorda-Sanchez I, Rodriguez-Pinilla E, Trujillo-Tiebas MJ, Jimenez-Rolando B, Carreño E, Mahillo-Fernandez I, Rivolta C, Corton M, Avila-Fernandez A, Garcia-Sandoval B, Ayuso C. Genotype-Phenotype Correlations in a Spanish Cohort of 506 Families With Biallelic ABCA4 Pathogenic Variants. Am J Ophthalmol. 2020;219:195–204. https://doi.org/10.1016/j.ajo.2020.06.027. Epub 2020 Jun 30.

    Article  CAS  PubMed  Google Scholar 

  57. Tomkiewicz TZ, Suárez-Herrera N, Cremers FPM, Collin RWJ, Garanto A. Antisense Oligonucleotide-Based Rescue of Aberrant Splicing Defects Caused by 15 Pathogenic Variants in ABCA4. Int J Mol Sci. 2021;22(9):4621. https://doi.org/10.3390/ijms22094621.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  58. Briggs CE, Rucinski D, Rosenfeld PJ, Hirose T, Berson EL, Dryja TP. Mutations in ABCR (ABCA4) in patients with Stargardt macular degeneration or cone-rod degeneration. Invest Ophthalmol Vis Sci. 2001;42(10):2229–36.

    CAS  PubMed  Google Scholar 

  59. Baralle D, Baralle M. Splicing in action: assessing disease causing sequence changes. J Med Genet. 2005;42(10):737–48. https://doi.org/10.1136/jmg.2004.029538.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Sun H, Smallwood PM, Nathans J. Biochemical defects in ABCR protein variants associated with human retinopathies. Nat Genet. 2000;26(2):242–6. https://doi.org/10.1038/79994.

    Article  CAS  PubMed  Google Scholar 

  61. Rosenberg T, Klie F, Garred P, Schwartz M. N965S is a common ABCA4 variant in Stargardt-related retinopathies in the Danish population. Mol Vis. 2007;13:1962–9.

    CAS  PubMed  Google Scholar 

  62. Braun TA, Mullins RF, Wagner AH, Andorf JL, Johnston RM, Bakall BB, Deluca AP, Fishman GA, Lam BL, Weleber RG, Cideciyan AV, Jacobson SG, Sheffield VC, Tucker BA, Stone EM. Non-exomic and synonymous variants in ABCA4 are an important cause of Stargardt disease. Hum Mol Genet. 2013;22(25):5136–45. https://doi.org/10.1093/hmg/ddt367.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Ozgül RK, Durukan H, Turan A, Oner C, Ogüs A, Farber DB. Molecular analysis of the ABCA4 gene in Turkish patients with Stargardt disease and retinitis pigmentosa. Hum Mutat. 2004;23(5):523. https://doi.org/10.1002/humu.9236.

    Article  CAS  PubMed  Google Scholar 

  64. Rozet JM, Gerber S, Souied E, Perrault I, Châtelin S, Ghazi I, Leowski C, Dufier JL, Munnich A, Kaplan J. Spectrum of ABCR gene mutations in autosomal recessive macular dystrophies. Eur J Hum Genet. 1998;6(3):291–5. https://doi.org/10.1038/sj.ejhg.5200221.

    Article  CAS  PubMed  Google Scholar 

  65. Cremers FPM, Lee W, Collin RWJ, Allikmets R. Clinical spectrum, genetic complexity and therapeutic approaches for retinal disease caused by ABCA4 mutations. Prog Retin Eye Res. 2020;79:100861. https://doi.org/10.1016/j.preteyeres.2020.100861.

  66. Xu Y, Guan L, Shen T, Zhang J, Xiao X, Jiang H, Li S, Yang J, Jia X, Yin Y, Guo X, Wang J, Zhang Q. Mutations of 60 known causative genes in 157 families with retinitis pigmentosa based on exome sequencing. Hum Genet. 2014;133(10):1255–71. https://doi.org/10.1007/s00439-014-1460-2.

    Article  PubMed  Google Scholar 

  67. Alkanderi S, Molinari E, Shaheen R, Elmaghloob Y, Stephen LA, Sammut V, Ramsbottom SA, Srivastava S, Cairns G, Edwards N, Rice SJ, Ewida N, Alhashem A, White K, Miles CG, Steel DH, Alkuraya FS, Ismail S, Sayer JA. ARL3 Mutations Cause Joubert Syndrome by Disrupting Ciliary Protein Composition. Am J Hum Genet. 2018;103(4):612–20. https://doi.org/10.1016/j.ajhg.2018.08.015.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  68. Zaneveld J, Siddiqui S, Li H, Wang X, Wang H, Wang K, Li H, Ren H, Lopez I, Dorfman A, Khan A, Wang F, Salvo J, Gelowani V, Li Y, Sui R, Koenekoop R, Chen R. Comprehensive analysis of patients with Stargardt macular dystrophy reveals new genotype-phenotype correlations and unexpected diagnostic revisions. Genet Med. 2015;17(4):262–70. https://doi.org/10.1038/gim.2014.174. Epub 2014 Dec 4.

    Article  CAS  PubMed  Google Scholar 

  69. Perrault I, Hanein S, Zanlonghi X, Serre V, Nicouleau M, Defoort-Delhemmes S, Delphin N, Fares-Taie L, Gerber S, Xerri O, Edelson C, Goldenberg A, Duncombe A, Le Meur G, Hamel C, Silva E, Nitschke P, Calvas P, Munnich A, Roche O, Dollfus H, Kaplan J, Rozet JM. Mutations in NMNAT1 cause Leber congenital amaurosis with early-onset severe macular and optic atrophy. Nat Genet. 2012;44(9):975–7. https://doi.org/10.1038/ng.2357. Epub 2012 Jul 29.

    Article  CAS  PubMed  Google Scholar 

  70. den Hollander AI, Koenekoop RK, Yzer S, Lopez I, Arends ML, Voesenek KE, Zonneveld MN, Strom TM, Meitinger T, Brunner HG, Hoyng CB, van den Born LI, Rohrschneider K, Cremers FP. Mutations in the CEP290 (NPHP6) gene are a frequent cause of Leber congenital amaurosis. Am J Hum Genet. 2006;79(3):556–61. https://doi.org/10.1086/507318.

    Article  Google Scholar 

  71. Wang T, Waters CT, Rothman AM, Jakins TJ, Römisch K, Trump D. Intracellular retention of mutant retinoschisin is the pathological mechanism underlying X-linked retinoschisis. Hum Mol Genet. 2002;11(24):3097–105. https://doi.org/10.1093/hmg/11.24.3097.

    Article  CAS  PubMed  Google Scholar 

  72. Cohn AC, Turnbull C, Ruddle JB, Guymer RH, Kearns LS, Staffieri S, Daggett HT, Hewitt AW, Mackey DA. Best’s macular dystrophy in Australia: phenotypic profile and identification of novel BEST1 mutations. Eye (London, England). 2011;25(2):208–17. https://doi.org/10.1038/eye.2010.180.

    Article  CAS  PubMed  Google Scholar 

  73. Cesca F, Bettella E, Polli R, Leonardi E, Aspromonte MC, Sicilian B, Stanzial F, Benedicenti F, Sensi A, Ciorba A, Bigoni S, Cama E, Scimemi P, Santarelli R, Murgia A. Frequency of Usher gene mutations in non-syndromic hearing loss: higher variability of the Usher phenotype. J Hum Genet. 2020;65(10):855–64. https://doi.org/10.1038/s10038-020-0783-1. Epub 2020 May 28.

    Article  CAS  PubMed  Google Scholar 

  74. Eandi CM, Dallorto L, Spinetta R, Micieli MP, Vanzetti M, Mariottini A, Passerini I, Torricelli F, Alovisi C, Marchese C. Targeted next generation sequencing in Italian patients with Usher syndrome: phenotype-genotype correlations. Sci Rep. 2017;7(1):15681. https://doi.org/10.1038/s41598-017-16014-z.

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  75. Neuhaus C, Eisenberger T, Decker C, Nagl S, Blank C, Pfister M, Kennerknecht I, Müller-Hofstede C, Charbel Issa P, Heller R, Beck B, Rüther K, Mitter D, Rohrschneider K, Steinhauer U, Korbmacher HM, Huhle D, Elsayed SM, Taha HM, Baig SM, Stöhr H, Preising M, Markus S, Moeller F, Lorenz B, Nagel-Wolfrum K, Khan AO, Bolz HJ. Next-generation sequencing reveals the mutational landscape of clinically diagnosed Usher syndrome: copy number variations, phenocopies, a predominant target for translational read-through, and PEX26 mutated in Heimler syndrome. Mol Genet Genomic Med. 2017;5(5):531–52. https://doi.org/10.1002/mgg3.312.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  76. Wafa TT, Faridi R, King KA, Zalewski C, Yousaf R, Schultz JM, Morell RJ, Muskett J, Turriff A, Tsilou E, Griffith AJ, Friedman TB, Zein WM, Brewer CC. Vestibular phenotype-genotype correlation in a cohort of 90 patients with Usher syndrome. Clin Genet. 2021;99(2):226–35. https://doi.org/10.1111/cge.13868. Epub 2020 Nov 3.

    Article  CAS  PubMed  Google Scholar 

  77. Castiglione A, Möller C. Usher Syndrome. Audiol Res. 2022;12(1):42–65. https://doi.org/10.3390/audiolres12010005.

    Article  PubMed  PubMed Central  Google Scholar 

  78. Sloan-Heggen CM, Bierer AO, Shearer AE, Kolbe DL, Nishimura CJ, Frees KL, Ephraim SS, Shibata SB, Booth KT, Campbell CA, Ranum PT, Weaver AE, Black-Ziegelbein EA, Wang D, Azaiez H, Smith RJH. Comprehensive genetic testing in the clinical evaluation of 1119 patients with hearing loss. Hum Genet. 2016;135(4):441–50. https://doi.org/10.1007/s00439-016-1648-8.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  79. Dreyer B, Tranebjaerg L, Rosenberg T, Weston MD, Kimberling WJ, Nilssen O. Identification of novel USH2A mutations: implications for the structure of USH2A protein. Eur J Hum Genet. 2000;8(7):500–6. https://doi.org/10.1038/sj.ejhg.5200491.

    Article  CAS  PubMed  Google Scholar 

  80. Minton JA, Owen KR, Ricketts CJ, Crabtree N, Shaikh G, Ehtisham S, Porter JR, Carey C, Hodge D, Paisey R, Walker M, Barrett TG. Syndromic obesity and diabetes: changes in body composition with age and mutation analysis of ALMS1 in 12 United Kingdom kindreds with Alstrom syndrome. J Clin Endocrinol Metab. 2006;91(8):3110–6. https://doi.org/10.1210/jc.2005-2633.

    Article  CAS  PubMed  Google Scholar 

  81. Marshall JD, Hinman EG, Collin GB, Beck S, Cerqueira R, Maffei P, Milan G, Zhang W, Wilson DI, Hearn T, Tavares P, Vettor R, Veronese C, Martin M, So WV, Nishina PM, Naggert JK. Spectrum of ALMS1 variants and evaluation of genotype-phenotype correlations in Alström syndrome. Hum Mutat. 2007;28(11):1114–23. https://doi.org/10.1002/humu.20577.

    Article  CAS  PubMed  Google Scholar 

  82. Chandrasekar SP, Namboothiri S, Sen P, Sarangapani S. Screening formutation hotspots in Bardet-Biedl syndrome patients from India. Indian J MedRes. 2018;147(2):177–82. https://doi.org/10.4103/ijmr.IJMR_1822_15.

    Article  CAS  Google Scholar 

  83. Lenherr N, Christodoulou J, Duley J, Dobritzsch D, Fairbanks L, Datta AN, Filges I, Gürtler N, Roelofsen J, van Kuilenburg ABP, Kemper C, West EE, Szinnai G, Huemer M. Co-therapy with S-adenosylmethionine and nicotinamide riboside improves t-cell survival and function in Arts Syndrome (PRPS1 deficiency). Mol Genet Metab Rep. 2021;26:100709. https://doi.org/10.1016/j.ymgmr.2021.100709.

  84. Cryns K, Sivakumaran TA, Van den Ouweland JM, Pennings RJ, Cremers CW, Flothmann K, Young TL, Smith RJ, Lesperance MM, Van Camp G. Mutational spectrum of the WFS1 gene in Wolfram syndrome, nonsyndromic hearing impairment, diabetes mellitus, and psychiatric disease. Hum Mutat. 2003;22(4):275–87. https://doi.org/10.1002/humu.10258.

    Article  CAS  PubMed  Google Scholar 

  85. Hicks S, Wheeler DA, Plon SE, Kimmel M. Prediction of missense mutation functionality depends on both the algorithm and sequence alignment employed. Hum Mutat. 2011;32:661–8.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  86. Martinez-Fierro ML, Beuten J, Leach RJ, Parra EJ, Cruz-Lopez M, Rangel-Villalobos H, Riego-Ruiz LR, Ortiz-Lopez R, Martinez-Rodriguez HG, Rojas-Martinez A. Ancestry informative markers and admixture proportions in northeastern Mexico. J Hum Genet. 2009;54(9):504–9. https://doi.org/10.1038/jhg.2009.65.

  87. Rubi-Castellanos R, Martínez-Cortés G, Muñoz-Valle JF, González-Martín A, Cerda-Flores RM, Anaya-Palafox M, Rangel-Villalobos H. Pre-Hispanic Mesoamerican demography approximates the present-day ancestry of Mestizos throughout the territory of Mexico. Am J Phys Anthropol. 2009;139(3):284–94. https://doi.org/10.1002/ajpa.20980.

  88. Ordoñez-Labastida V, et al. USH2A mutational spectrum causing syndromic and non-syndromic retinal dystrophies in a large cohort of Mexican patients. Mol Vis. 2023;29:31–8. PMID: 37287646; PMCID: PMC10243674.

    PubMed  PubMed Central  Google Scholar 

  89. GenomeAD version 4.0.0. https://gnomad.broadinstitute.org/variant/1-216247094-TC-T?dataset=gnomad_r4. (Revised on Nov. 26, 2023).

  90. Dreyer B, et al. A common ancestral origin of the frequent and widespread 2299delG USH2A mutation. Am J Hum Genet. 2001;69(1):228–34. https://doi.org/10.1086/321269. Epub 2001 Jun 8.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  91. Villafuerte-de la Cruz R, et al. Case report: disease phenotype associated with simultaneous biallelic mutations in ABCA4 and USH2A due to uniparental disomy of chromosome 1. Front Genet. 2022;13:949437.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  92. National Library of Medicine, ClinVar. “NM_000180.4(GUCY2D):c.2795T > G (p.Met932Arg)”. Record last updated Feb 07, 2023. Visited on 22.11.2023. https://www.ncbi.nlm.nih.gov/clinvar/variation/1053499/.

Download references

Acknowledgements

The authors acknowledge Invitae Corporation for providing access to their IRD program for our patients. The authors would also like to acknowledge the working personnel from Santos y de la Garza Evia Foundation, Destellos de Luz Foundation, Instituto de la Visión-Hospital La Carlota, and every patient participating in the present study.

The authors would also like to acknowledge the scholarship given by Tecnologico de Monterrey to RAVC for her PhD studies.

Funding

No monetary funding was obtained for the present paper.

Author information

Authors and Affiliations

Authors

Contributions

Conceptualization: RAVC, JEVG, ARM. Methodology: RAVC, CRT, ARM. Data analysis: RAVC, CRT, LGG, MAGL, ARM. Original draft writing: RAVC, LGG, MAGL, ARM. Manuscript revision and edition: RAVC, LGG, MAGL, JEVG, ARM. Project supervision: ARM.All authors reviewed the manuscript: RAVC, LAGG, MGL, CRT, CPB, DRG, ARP, AEBP, JANG, JCV, ECL, AVP, JEVG, ARM, IVCColaborated in making results available online in LOVD database: LAGG, RAVC, ARM, CPB, DRG, IVC.

Corresponding author

Correspondence to Augusto Rojas-Martinez.

Ethics declarations

Ethics approval and consent to participate

The present paper was approved by the local ethics committee [Institutional Review Board, School of Medicine at Tecnologico de Monterrey (code P000625-DIMDRET-CEIC-CR001)] and all procedures were conducted in compliance with the Declaration of Helsinki. In addition, written informed consent was obtained from all the patients or their legal guardians.

Consent to publication

Not applicable. No identifiable information is revealed in the present manuscript.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Additional file 1: Supplementary Table 1.

Demographic and clinical characteristics of study participants.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Villafuerte-de la Cruz, R.A., Garza-Garza, L.A., Garza-Leon, M. et al. Spectrum of variants associated with inherited retinal dystrophies in Northeast Mexico. BMC Ophthalmol 24, 60 (2024). https://doi.org/10.1186/s12886-023-03276-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s12886-023-03276-7

Keywords