A New Arg54Gly Transthyretin Gene Mutation Associated with Vitreous Amyloidosis in Chinese

Purpose:To analyse the hereditary features of a Chinese pedigree with familial vitreous amyloidosis in Liaoning Province,China,and to investigate the correlation between the clinical appearance of the disease and transthyretin(TTR)gene mutation,including the locus and type of TTR gene mutation.Methods:Five patients (10 eyes) from one Chinese family were diagnosed with vitreous amyloidosis between July 1996 and April 2009.Family members were followed up subsequently,and peripheral venous blood was obtained from 13 subjects (including 2 patients,and 11 controls without clinical signs of disease).DNA samples were extracted and 4 exons of the TTR gene were amplified by polymerase chain reaction (PCR).The gene fragments were subjected to sequencing analysis.The results were analyzed with DNAMAN Windows 5.2.2.0 and Chromas sequence chart analysis software,TTR gene exons were compared between affected patients and normal controls.Results:Family pedigree analysis revealed that patients were distributed in three generations.Male and female subjects had equal prevalence,and only one parent of affected patients had signs of disease.TTR gene exon sequencing showed that the sequence of patients was identical to that of normal individuals.No TTR gene mutations were noted in 10 unaffected family members.However,a TTR Gly-54 point mutation in the 2nd exon was detected in two patients and 1 unaffected family member (one of the patients’ daughters).Vitreous samples in 4 cases (7 eyes) showed positive Congo red staining,suggesting that these family members suffered from familial vitreous amyloidosis.Conclusion:This pedigree affected with familial vitreous amyloidosis was characterized by autosomal dominant inheritance;.a TTR Gly-54 point mutation in the 2nd exon is presumed to be the cause.This Gly-54 point mutation of the TTR gene is a novel mutation in vitreous amyloidosis.