A New Mutation Of LCA5 Gene In A Pedigree With Leber’s Congenital Amaurosis

PurposeLeber’s congenital amaurosis(LCA)was first described by Theodore Leber in 1869.It is a rare hereditary retinal disease accounting for at least 5%of all retinal dystrophy that is most often diagnosed in the first six months of life.In this study,the molecular genetics of a Chinese pedigree with LCA type 5 was studied by the Next-generation Sequencing technique,and its genotype-phenotypic correlation was analyzed.MethodsA total of nine Chinese Leber’s congenital amaurosis pedigrees,including two patients and seven normal family members,were collected from the ophthalmic clinic of the First Affiliated Hospital of Zhengzhou University.Blood samples of nine family members were collected,and 100 unrelated healthy persons were randomly collected as controls.All subjects were examined to exclude systemic diseases.Nine members of the family carried out detailed ophthalmic examination,including vision examination,electroretinogram,fundus photography,slit lamp microscopy,etc.This study has been approved by the ethics committee of Zhengzhou University and all members have signed the informed consent form.DNA of peripheral blood was extracted and sequenced for the Next-generation Sequencing technique.Sanger sequencing was used to verify the variations.The bioinformatics software Mutation Taster were used to predict and analyze the pathogenicity of protein.ResultsAccording to the clinical examination of Ophthalmology,family investigation and pedigree,the family patients were diagnosed clinically.All patients showed ocular abnormalities without systemic diseases.Two patients in this family met the diagnostic criteria of LCA,and the family characteristics were consistent with autosomal recessive inheritance.The clinical phenotypes of two patients in the family were similar,which showed low vision,night blindness,nystagmus,absence of electrical signal in electroretinogram and normal retina at 6 months after birth.In this LCA family,we found the LCA5 gene mutation:c.1457-1461delACCCinsTTTTTGC CATTGTTTTGCCAT(p.Y486Ffs)and c.425-436 delACAGGAGAAAG insTACAG(p.142-145delRQEKinsST).The mutation were found in the LCA5 gene of two patients and their parents in the family,but in normal relatives,the same changes were not found.The software of bioinformatics indicated that they were pathogenic changes.The results showed that the two point mutations did not exist in the normal controls.Sanger sequencing was carried out on DNA samples of other members of the family.The mutation sites of the proband were verified and genotype phenotype co-segregated analysis was carried out.The results of co-segregated analysis showed that the heterozygous mutation of LCA5 gene was co-segregated with the disease phenotype in this family.ConclusionsIn this study,we found two new pathogenic mutations in LCA5 gene in a Leber’s congenital amaurosis family:c.1457-1461delACCCins TTTTTGCCA TTGT TTTG CCAT(p.Y486Ffs),c.425-436delACAGGAGAAAG insTACAGinsTACAG(p.142-145delRQEKinsST).The mutations of these two sites may be the pathogenic mutations of the patients in the family.These findings broaden the mutation spectrum of Leber’s congenital amaurosis,provide reference for prenatal diagnosis of Leber’s congenital amaurosis,and accumulate the basis for gene therapy research.