scholarly journals Autosomal Recessive Retinitis Pigmentosa Associated with Three Novel REEP6 Variants in Chinese Population

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 537
Author(s):  
Lujia Zhang ◽  
Ya Li ◽  
Litao Qin ◽  
Yu Wu ◽  
Bo Lei

Retinitis pigmentosa 77 is caused by mutations of REEP6 (MIM: 609346), which encodes a protein for the development of photoreceptors. Our study was to identify disease-causing variants in three Chinese families using targeted next-generation sequencing (NGS). Multiple lines of computational predictions combined with in vitro cellular experiments were applied to evaluate the pathogenicity of the newly found variants. Three novel variants in REEP6, including one missense variant, c.268G>C, one frameshift variant, c.468delC, and one splicing variant, c.598+1G>C, were found, while c.268G>C was detected in all probands. The three variants were classified as likely pathogenic by the American College of Medical Genetics and Genomics (ACMG). REEP6 variant proteins c.268G>C and c.468delC in cultured cells destabilized the REEP6 protein and induced intracellular inclusions. Our data suggested that REEP6 c.268G>C may be a recurrent causative variant in Chinese autosomal recessive retinitis pigmentosa patients.

2021 ◽  
Author(s):  
Yuyu Li ◽  
Ruyi Li ◽  
Hehua Dai ◽  
Genlin Li

Abstract Background: Retinitis pigmentosa (RP) is a genetically heterogeneous disease with 65 causative genes identified to date. However, only approximately 60% of RP cases genetically solved to date, predicating that many novel disease-causing variants are yet to be identified. The purpose of this study is to identify novel variants in phosphodiesterase 6A and phosphodiesterase 6B genes and present its phenotypes in patients with retinitis pigmentosa in Chinese families.Methods: Five retinitis pigmentosa patients with PDE6A variants and three with PDE6B variants were identified through a hereditary eye disease enrichment panel (HEDEP), all patients’ medical and ophthalmic histories were collected, and ophthalmological examinations were performed, then we analysed the possible causative variants. Sanger sequencing was used to verify the variants.Results: We identified 20 mutations sites in eight patients, two heterozygous variants were identified per patient of either PDE6A or PDE6B variants, others are from CA4, OPTN, RHO, ADGRA3 variants. We identified two novel variants in PDE6A: c.1246G > A;p.(Asp416Asn) and c.1747T > A;p.(Tyr583Asn). Three novel mutations in PDE6B: c.401T > C;p.(Leu134Pro), c.2293G > C;p.(Ala765Pro) and c.1610-1612del;p.(537-538del).CA4: c.243G > A;p.(Trp81*) and RHO: c.688G>A;p.(Val230Ile) are novel variants and maybe affecting the phenotype. Among them, c.401T > C;p.(Leu134Pro) variant in PDE6B is non- pathogenic; RHO: c.688G>A;p.(Val230Ile) is conflicting interpretations of pathogenicity;Other novel variants are all pathogenic.Conclusions: This study reveals novel and known variants in Chinese families with PDE6A and PDE6B mutations in autosomal recessive RP, expanding the clinical and genetic findings of photoreceptor-specific enzyme deficiencies.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Raquel Perez-Carro ◽  
Marta Corton ◽  
Iker Sánchez-Navarro ◽  
Olga Zurita ◽  
Noelia Sanchez-Bolivar ◽  
...  

Abstract Retinitis pigmentosa (RP) is a group of inherited progressive retinal dystrophies (RD) characterized by photoreceptor degeneration. RP is highly heterogeneous both clinically and genetically, which complicates the identification of causative genes and mutations. Targeted next-generation sequencing (NGS) has been demonstrated to be an effective strategy for the detection of mutations in RP. In our study, an in-house gene panel comprising 75 known RP genes was used to analyze a cohort of 47 unrelated Spanish families pre-classified as autosomal recessive or isolated RP. Disease-causing mutations were found in 27 out of 47 cases achieving a mutation detection rate of 57.4%. In total, 33 pathogenic mutations were identified, 20 of which were novel mutations (60.6%). Furthermore, not only single nucleotide variations but also copy-number variations, including three large deletions in the USH2A and EYS genes, were identified. Finally seven out of 27 families, displaying mutations in the ABCA4, RP1, RP2 and USH2A genes, could be genetically or clinically reclassified. These results demonstrate the potential of our panel-based NGS strategy in RP diagnosis.


2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Yuyu Li ◽  
Ruyi Li ◽  
Hehua Dai ◽  
Genlin Li

Abstract Background Retinitis pigmentosa (RP) is a genetically heterogeneous disease with 89 causative genes identified to date. However, only approximately 60% of RP cases genetically solved to date, predicating that many novel disease-causing variants are yet to be identified. The purpose of this study is to identify novel variants in PDE6A and PDE6B genes and present its phenotypes in patients with retinitis pigmentosa in Chinese families. Methods Five retinitis pigmentosa patients with PDE6A variants and three with PDE6B variants were identified through a hereditary eye disease enrichment panel (HEDEP), all patients’ medical and ophthalmic histories were collected, and ophthalmological examinations were performed, followed by an analysis of the possible causative variants. Sanger sequencing was used to verify the variants. Results We identified 20 variants in eight patients: 16 of them were identified in either PDE6A or PDE6B in a compound heterozygous state. Additional four heterozygous variants were identified in the genes ADGRA3, CA4, OPTN, RHO. Two novel genetic changes in PDE6A were identified (c.1246G > A and c.1747 T > A), three novel genetic changes in PDE6B were identified (c.401 T > C, c.2293G > C and c.1610-1612del), out of the novel identified variants one was most probably non-pathogenic (c.2293G > C), all other novel variants are pathogenic. Additional variant was identified in CA4 and RHO, which can cause ADRP (c.243G > A, c.688G > A). In addition, a novel variant in ADGRA3 was identified (c.921-1G > A). Conclusions This study reveals novel and known variants in PDE6A and PDE6B genes in Chinese families with autosomal recessive RP, and expands the clinical and genetic findings of photoreceptor-specific enzyme deficiencies.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ine Strubbe ◽  
Caroline Van Cauwenbergh ◽  
Julie De Zaeytijd ◽  
Sarah De Jaegere ◽  
Marieke De Bruyne ◽  
...  

AbstractWe describe both phenotype and pathogenesis in two male siblings with typical retinitis pigmentosa (RP) and the potentially X-linked RP (XLRP) carrier phenotype in their mother. Two affected sons, two unaffected daughters, and their mother underwent detailed ophthalmological assessments including Goldmann perimetry, color vision testing, multimodal imaging and ISCEV-standard electroretinography. Genetic testing consisted of targeted next-generation sequencing (NGS) of known XLRP genes and whole exome sequencing (WES) of known inherited retinal disease genes (RetNet-WES). Variant validation and segregation analysis were performed by Sanger sequencing. The mutational load of the RHO variant in the mother was assessed in DNA from leucocytes, buccal cells and hair follicles using targeted NGS. Both affected sons showed signs of classical RP, while the mother displayed patches of hyperautofluorescence on blue light autofluorescence imaging and regional, intraretinal, spicular pigmentation, reminiscent of a carrier phenotype of XLRP. XLRP testing was negative. RetNet-WES testing revealed RHO variant c.404G > C p.(Arg135Pro) in a mosaic state (21% of the reads) in the mother and in a heterozygous state in both sons. Targeted NGQSS of the RHO variant in different maternal tissues showed a mutation load between 25.06% and 41.72%. We report for the first time that somatic mosaicism of RHO variant c.404G > C p.(Arg135Pro) mimics the phenotype of a female carrier of XLRP, in combination with heterozygosity for the variant in the two affected sons.


2018 ◽  
Author(s):  
Gabrielle Wheway ◽  
Liliya Nazlamova ◽  
Nervine Meshad ◽  
Samantha Hunt ◽  
Nicola Jackson ◽  
...  

AbstractAt least six different proteins of the spliceosome, including PRPF3, PRPF4, PRPF6, PRPF8, PRPF31 and SNRNP200, are mutated in autosomal dominant retinitis pigmentosa (adRP). These proteins have recently been shown to localise to the base of the connecting cilium of the retinal photoreceptor cells, elucidating this form of RP as a retinal ciliopathy. In the case of loss-of-function variants in these genes, pathogenicity can easily be ascribed. In the case of missense variants, this is more challenging. Furthermore, the exact molecular mechanism of disease in this form of RP remains poorly understood.In this paper we take advantage of the recently published cryo EM-resolved structure of the entire human spliceosome, to predict the effect of a novel missense variant in one component of the spliceosome; PRPF31, found in a patient attending the genetics eye clinic at Bristol Eye Hospital. Monoallelic variants in PRPF31 are a common cause of autosomal dominant retinitis pigmentosa (adRP) with incomplete penetrance. We use in vitro studies to confirm pathogenicity of this novel variant PRPF31 c.341T>A, p.Ile114Asn.This work demonstrates how in silico modelling of structural effects of missense variants on cryo-EM resolved protein complexes can contribute to predicting pathogenicity of novel variants, in combination with in vitro and clinical studies. It is currently a considerable challenge to assign pathogenic status to missense variants in these proteins.


2019 ◽  
Vol 39 (10) ◽  
Author(s):  
Jiewen Fu ◽  
Jingliang Cheng ◽  
Qi Zhou ◽  
Chunli Wei ◽  
Hanchun Chen ◽  
...  

Abstract The mutations in patients with X-linked retinitis pigmentosa (xlRP) have not been well described in the Chinese population. In the present study, a five-generation Chinese retinitis pigmentosa (RP) family was recruited; targeted next-generation sequencing (TGS) was used to identify causative genes and Sanger sequencing for co-segregation. RNA-seq data analysis and revere transcriptional-polymerase chain reaction (RT-PCR) were applied to investigate gene expression patterns of RP GTPase regulator (RPGR) in human and Rpgr in mouse. A novel, hemizygous, deleterious and missense variant: c.G644A (p.G215E) in the RPGR gene (NM_000328.2) exon 7 of X-chromosome was identified in the proband, which was co-segregated with the clinical phenotypes in this family. RNA-seq data showed that RPGR is ubiquitously expressed in 27 human tissues with testis in highest, but no eye tissues data. Then the expressions for Rpgr mRNA in mice including eye tissues were conducted and showed that Rpgr transcript is ubiquitously expressed very highly in retina and testis, and highly in other eye tissues including lens, sclera, and cornea; and expressed highly in the six different developmental times of retinal tissue. Ubiquitous expression in different tissues from eye and very high expression in the retina indicated that RPGR plays a vital role in eye functions, particularly in retina. In conclusion, our study is the first to indicate that the novel missense variant c.G644A (p.G215E) in the RPGR gene might be the disease-causing mutation in this xlRP family, expanding mutation spectrum. These findings facilitate better understanding of the molecular pathogenesis of this disease; provide new insights for genetic counseling and healthcare.


2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Ling-hui Qu ◽  
Xin Jin ◽  
Yan-ling Long ◽  
Jia-yun Ren ◽  
Chuang-huang Weng ◽  
...  

Abstract Background: The USH2A gene encodes usherin, a basement membrane protein that is involved in the development and homeostasis of the inner ear and retina. Mutations in USH2A are linked to Usher syndrome type II (USH II) and non-syndromic retinitis pigmentosa (RP). Molecular diagnosis can provide insight into the pathogenesis of these diseases, facilitate clinical diagnosis, and identify individuals who can most benefit from gene or cell replacement therapy. Here, we report 21 pathogenic mutations in the USH2A gene identified in 11 Chinese families by using the targeted next-generation sequencing (NGS) technology. Methods: In all, 11 unrelated Chinese families were enrolled, and NGS was performed to identify mutations in the USH2A gene. Variant analysis, Sanger validation, and segregation tests were utilized to validate the disease-causing mutations in these families. Results: We identified 21 pathogenic mutations, of which 13, including 5 associated with non-syndromic RP and 8 with USH II, have not been previously reported. The novel variants segregated with disease phenotype in the affected families and were absent from the control subjects. In general, visual impairment and retinopathy were consistent between the USH II and non-syndromic RP patients with USH2A mutations. Conclusions: These findings provide a basis for investigating genotype–phenotype relationships in Chinese USH II and RP patients and for clarifying the pathophysiology and molecular mechanisms of the diseases associated with USH2A mutations.


2021 ◽  
Vol 12 ◽  
Author(s):  
Linya Ma ◽  
Jianjian Zhu ◽  
Jing Wang ◽  
Yazhou Huang ◽  
Jibo Zhang ◽  
...  

BackgroundTyrosinase-positive oculocutaneous albinism (OCA, type II, OCA2) is an autosomal recessive genetic disease in which the biosynthesis of melanin decreases in the skin, hair, and eyes. OCA2 disease is caused by mutations in OCA2 gene. The gene product plays a role in regulating the pH of melanosomes. Up to now, hundreds of OCA2 mutations have been reported and novel variants are still being discovered.MethodsIn this study, we reviewed the records of OCA2 patients who had conducted albinism genetic testing, and then analyzed the clinical and genetic information of 28 OCA2 patients who had been genetically diagnosed by using Sanger sequencing and next-generation sequencing.ResultsIn this study, we reported 31 variants screened from 28 Chinese OCA2 families, and characterized the detailed molecular and clinical presentations. There were 12 novel variants among all detected variants, including 3 missense variants (p.G393V, p.T482A, and p.R720P), 4 frameshift variants (p.R53Gfs∗49, p.N279Kfs∗17, p.I469Lfs∗4, p.I655Nfs∗12), 2 splicing variants (c.1637-2A > G, c.1951 + 1G > C), 2 stopgain variants (p.L278X, p.W652X) and 1 insertion variants (p.P315LinsT). One potential cluster of missense variants was implicated indicating the important roles of the underlying domains in OCA2 pathogenesis.ConclusionOur results were beneficial for diagnosis and precision clinical management for OCA2-related disorder, and this study expanded the mutation spectrum of oculocutaneous albinism.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xiao-Hui Wang ◽  
Le Xie ◽  
Sen Chen ◽  
Kai Xu ◽  
Xue Bai ◽  
...  

Congenital deafness is one of the most common causes of disability in humans, and more than half of cases are caused by genetic factors. Mutations of the MYO15A gene are the third most common cause of hereditary hearing loss. Using next-generation sequencing combined with auditory tests, two novel compound heterozygous variants c.2802_2812del/c.5681T>C and c.5681T>C/c.6340G>A in the MYO15A gene were identified in probands from two irrelevant Chinese families. Auditory phenotypes of the probands are consistent with the previously reported for recessive variants in the MYO15A gene. The two novel variants, c.2802_2812del and c.5681T>C, were identified as deleterious mutations by bioinformatics analysis. Our findings extend the MYO15A gene mutation spectrum and provide more information for rapid and precise molecular diagnosis of congenital deafness.


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