Comprehensive genotyping reveals RPE65 as the most frequently mutated gene in Leber congenital amaurosis in Denmark

Abstract

Leber congenital amaurosis (LCA) represents the most severe form of inherited retinal dystrophies with an onset during the first year of life. Currently, 21 genes are known to be associated with LCA and recurrent mutations have been observed in AIPL1, CEP290, CRB1 and GUCY2D. In addition, sequence analysis of LRAT and RPE65 may be important in view of treatments that are emerging for patients carrying variants in these genes. Screening of the aforementioned variants and genes was performed in 64 Danish LCA probands. Upon the identification of heterozygous variants, Sanger sequencing was performed of the relevant genes to identify the second allele. In combination with prior arrayed primer extension analysis, this led to the identification of two variants in 42 of 86 cases (49%). Remarkably, biallelic RPE65 variants were identified in 16% of the cases, and one novel variant, p.(D110G), was found in seven RPE65 alleles. We also collected all previously published RPE65 variants, identified in 914 alleles of 539 patients with LCA or early-onset retinitis pigmentosa, and deposited them in the RPE65 Leiden Open Variation Database (LOVD). The in silico pathogenicity assessment of the missense and noncanonical splice site variants, as well as an analysis of their frequency in~60 000 control individuals, rendered 864 of the alleles to affect function or probably affect function. This comprehensive database can now be used to select patients eligible for gene augmentation or retinoid supplementation therapies.

Leber congenital amaurosis/early-onset severe retinal dystrophy: clinical features, molecular genetics and therapeutic interventions

“…8 These genes have been shown to encode proteins with a diverse range of retinal functions, including phototransduction, the visual cycle and photoreceptor development/integrity (table 1, figure 1). [9][10][11] Given recent advances in understanding of the molecular basis of these disorders and the ongoing clinical trials of novel therapies, we herein review the clinical characteristics, animal models and pathophysiology of LCA/EOSRD, prioritising the more common genotypes and/or those closest to intervention.…”

RPE65 mutation frequency and phenotypic variation according to exome sequencing in a tertiary centre for genetic eye diseases in China

“…Therefore, biallelic RPE65 mutations contributed to approximately 3.0% (8/269) of LCA and 0.8% (18/2133) of HRD cases. Clinically, diseases in 13 of the 18 families could be classified as LCA or EORD, which are common phenotypes previously reported to be associated with RPE65 mutations (Gu et al 1997;Marlhens et al 1997;Morimura et al 1998;Thompson et al 2000;Simovich et al 2001;Yzer et al 2003;Booij et al 2005;El Matri et al 2006;Simonelli et al 2007;Li et al 2009;Xu et al 2012;Kabir et al 2013;Verma et al 2013;Astuti et al 2016;Katagiri et al 2016). In the remaining five families with biallelic RPE65 mutations, we unexpectedly found that the phenotypes were FA-like changes in four families and high hyperopia in one family.…”

Clinical Characterization of 66 Patients With Congenital Retinal Disease Due to the Deep-Intronic c.2991+1655A>G Mutation inCEP290

“…Detected variants were amplified, Sanger sequenced, and finally validated with independent polymerase chain reactions (PCR). 26 The German cohort was analyzed using direct Sanger sequencing, APEX, and next-generation sequencing.…”