0 avis
Run of homozygosity analysis reveals a novel nonsense variant of the CNGB1 gene involved in retinitis pigmentosa 45
Archive ouverte
Edité par CCSD ; Taylor & Francis -
International audience. BACKGROUND: Retinitis pigmentosa (RP) is a group of retinal disorders with clinical and genetic heterogeneity characterized by the progressive dysfunction of photoreceptors. Mutations in the CNGB1 gene are involved in a rare autosomal recessive form of RP (RP45). We report the case of a 51-year-old woman, born of consanguineous parents (f = 1/32) of French origin, affected with non-syndromic RP.MATERIALS AND METHODS: Homozygosity mapping was performed on this patient and her two unaffected brothers using oligonucleotide arrays containing 300,000 markers including 200,000 single nucleotide polymorphisms.RESULTS: The largest homozygous region not shared by the patient and her brothers was a 23Mb region containing the CNGB1 gene situated on chromosome 16q12.1q23. Subsequent Sanger sequencing of CNGB1 identified a nonsense variant (p.Trp313*) segregating with the disease.CONCLUSIONS: To date, only 13 pathogenic CNGB1 variants have been reported in studies of 12 families. Six unrelated index patients were homozygous for a missense variant, four were homozygous for a splice-site variant, and two were compound heterozygous for nonsense and frameshift variants. The patient we report here is the first to be found homozygous for a novel nonsense CNGB1 variant. Our finding underscores the clinical usefulness of a genotype-first approach in recessive RP
Consulter en ligne
Suggestions
Du même auteur
