先天性甲状腺功能减退症患儿的甲状腺球蛋白基因突变研究

Identifying the thyroglobulin mutations from patients with congenital hypothyroidism

目的研究甲状腺球蛋白(thyroglobulin, TG)基因在中国先天性甲状腺功能减退症(先天性甲减)患儿中的突变及其家系遗传规律。方法 2014年至2018年本课题组收集235例先天性甲减患儿及部分家系的临床资料并留取外周血, 提取外周血DNA, 设计TG基因各个外显子区及其外显子-内含子交界区的引物扩增TG基因, 然后利用二代测序技术及生物信息学分析获取TG基因的突变并进行Sanger测序验证。另外对其中2例携带有TG基因复合杂合突变患儿的父母进行Sanger测序验证。结果在235例先天性甲减患儿中, 携带TG基因变异位点的患儿有34例(14.47%), 其中6例(2.55%)患儿携带复合杂合突变。此外, 在这些TG基因变异位点中, 1个位点为热点突变(4例患儿携带T1620M), 9个变异为新发现的位点(T601M、V2423I、R2308S、C2005R、C2264F、L987R、K1645Efs*49、F311Lfs*91和T1416M)。结论 TG基因在中国先天性甲减的患儿中突变率较高, 为常染色体隐性遗传模式。

Objective This study aimed to identify mutations of the thyroglobulin(TG)gene and inheritance patterns in Chinese patients with congenital hypothyroidism.Methods Clinical data of 235 children with congenital hypothyroidism and some of their families were collected from 2014 to 2018,and peripheral blood samples were collected for DNA extraction.Genomic DNA was extracted from the peripheral blood and TG gene was amplified with primers designed for each exon region and exon-intron junction region.Next generation sequencing technology and bioinformatics analysis were used to obtain TG gene mutations,followed by validation through Sanger sequencing.In addition,two compound heterozygotes with TG mutations and their parents were tested by Sanger sequencing.Results Among 235 patients with congenital hypothyroidism,thirty-four cases(14.47%)carried TG gene variants,of which 6 cases(2.55%)carried compound heterozygous mutations.In addition,one of these TG gene variants was a hotspot mutation(T1620M was carried by four patients),nine were novel mutations(T601M,V2423I,R2308S,C2005R,C2264F,L987R,K1645Efs*49,F311Lfs*91,and T1416M).Conclusion The mutation rate of the TG gene is higher in Chinese patients with congenital hypothyroidism,and two pedigrees indicated an autosomal recessive inheritance pattern.