Analysis of TGFBI gene mutation in a Chinese family with Avellino corneal dystrophies

Abstract

Background Researches demonstrated that corneal dystrophy is associated with the mutation of transforming growth factor beta induced gene(TGFBI)located at chromosome 5q31 domine.Recent study showed that the gene mutation location is in R124H of TGFBI gene. Objective This study was to identify the mutation characteristics of TGFBI gene in a Chinese family with Avellino corneal dystrophy. Methods This Chinese family with Avellino corneal dystrophy were determined and surveyed in Peking University Third Hospital.Periphery blood from 8 patients with Avellino corneal dystrophy and 2 unaffected subjects were collected from a Chinese family with corneal dystrophy for the extraction of DNA.Exons 4,11,12 of the TGFBI gene were amplified by polymerase chain reaction(PCR),and the amplified products were sequenced directly and compared the gene sequence with that of TGFBI in GenBank.Written informed consent was obtained from each Subject prior to any medieal process. Results This family included 27 members of consecutive 4 generation.The hereditary pattern W88 in accordance with the autosomal dominant inheritance.Directly sequencing of 8 affected members revealed a G tO A transition at codon 124 (CGC to CAC),producing R124H mutation of TGFBI gene.Two synonymous single nucleotide polymorphism(SNP)of TGFBI gene occurred in the family.including a C to T transition at eodon 472(CTC to CTT)in 8 members,and a T to C transition at codon 540(TTT>TTC)in 9 members,which wag unrelated with disease. Conclusion R124H mutation of the TGFBI gene is found in this Chinese family with Avellino corneal dystrophy. Key words: Corneal dystrophy; Transforming growth factor beta induce gene; Mutation; Heterozygote