Background： Leber congenital amaurosis （LCA） is a group of clinically and genetically heterogeneous retinal dystrophy. To date, 22 genes are known to be responsible for LCA, and some specific phenotypic features co...Background： Leber congenital amaurosis （LCA） is a group of clinically and genetically heterogeneous retinal dystrophy. To date, 22 genes are known to be responsible for LCA, and some specific phenotypic features could provide significant prognostic information for a potential genetic etiology. This study is to identify gene variants responsible for LCA in a Chinese family using direct Sanger sequencing, with the help of phenotype-genotype correlations. Methods： A Chinese family with six members including two individuals affected with t.CA was studied. All pa- tients underwent a complete ophthalmic examination. Based on phenotype-genotype correlation, direct Sanger sequencing was performed to identify the candidate gene on all family members and normal controls. Targeted next-generation sequencing was used to exclude other known LCA genes. Results： By Sanger sequencing, we identified two novel missense variants in the retinol dehydrogenase 12 （RDH12） gene： a c. 164C〉A transversion predicting a p.T55K substitution, and a c.535C〉G transversion predicting a p.H179D substitution. The two affected subjects carried both RDH12 variants, while their parents and offspring carried only one of heterozygous variants, showing complete cosegregation of the variants. The compound heterozygous variants were not present in 600 normal controls Besides, the RDH12 variants were confirmed by targeted next-generation sequencing. Conclusions： The RDH12 compound heterozygous variants might be the cause of the LCA family. Our study adds to the molecular spectrum of RDH12-related retinopathy and offers an effective example of the power of phenotype-genotype correlations in molecular diagnosis of LCA.展开更多
基金supported by the National Natural Science Foundation of China(No.81300741)
文摘Background： Leber congenital amaurosis （LCA） is a group of clinically and genetically heterogeneous retinal dystrophy. To date, 22 genes are known to be responsible for LCA, and some specific phenotypic features could provide significant prognostic information for a potential genetic etiology. This study is to identify gene variants responsible for LCA in a Chinese family using direct Sanger sequencing, with the help of phenotype-genotype correlations. Methods： A Chinese family with six members including two individuals affected with t.CA was studied. All pa- tients underwent a complete ophthalmic examination. Based on phenotype-genotype correlation, direct Sanger sequencing was performed to identify the candidate gene on all family members and normal controls. Targeted next-generation sequencing was used to exclude other known LCA genes. Results： By Sanger sequencing, we identified two novel missense variants in the retinol dehydrogenase 12 （RDH12） gene： a c. 164C〉A transversion predicting a p.T55K substitution, and a c.535C〉G transversion predicting a p.H179D substitution. The two affected subjects carried both RDH12 variants, while their parents and offspring carried only one of heterozygous variants, showing complete cosegregation of the variants. The compound heterozygous variants were not present in 600 normal controls Besides, the RDH12 variants were confirmed by targeted next-generation sequencing. Conclusions： The RDH12 compound heterozygous variants might be the cause of the LCA family. Our study adds to the molecular spectrum of RDH12-related retinopathy and offers an effective example of the power of phenotype-genotype correlations in molecular diagnosis of LCA.
