不明原因男性不育人群中睾丸特异性乳酸脱氢酶基因突变的发现及其意义  

A Mutation of Testis-specific Lactate Dehydrogenase Gene Found in Male Patients With Unexplained Infertility

作　　者：李博[1] 张朵[1] 曾健[1] 富显果[1] 柯龙凤[1] 颜水堤[1] 严爱贞[1] 兰风华[1] 

机构地区：[1]南京军区福州总医院临床遗传与实验医学科,福州350025

出　　处：《生物化学与生物物理进展》2010年第4期445-450,共6页Progress In Biochemistry and Biophysics

基　　金：福建省重点科技攻关项目(2002Y032);全军医药卫生"十五"基金项目(01MA032)~~

摘　　要：为了研究睾丸特异性乳酸脱氢酶,即乳酸脱氢酶C4(LDH-C4)基因突变在男性不育发病中的作用,利用LDH-C4特异性底物对100名不明原因男性不育症患者的精子LDH-C4进行活性显色,用变性高效液相色谱(DHPLC)技术对LDH-C4活性低下的患者进行LDHC基因PCR产物的突变筛查,对DHPLC峰形异常的PCR产物进行序列测定.筛选到一组精子LDH-C4活性明显下降的患者,其中1名患者的LDHC基因PCR产物在DHPLC中呈异常洗脱峰.对这一PCR产物进行序列测定,发现患者LDHC基因第5外显子的115位碱基发生了T→A的杂合改变(GenBank登录号GU479375),该突变使LDHC基因的178位密码子由原来的TTG(编码亮氨酸)变为TAG(终止密码子),形成截短的C亚基.T克隆-测序进一步证实了该无义突变的杂合状态.这是在人类LDHC基因上发现的第一个突变,提示LDHC基因突变可能是男性不育发病的原因之一.To investigate the role played by mutations of LDHC gene in male infertility, 100 male patients with unexplained infertility were screened by activity staining of LDH-C4 on sperm smears and those with lowered or no LDH-C4 activity in their sperms were subject to DNA analysis. The encoding exons were PCR amplified and the PCR products were screened by DHPLC for mutations. The PCR products with abnormal elution peaks were subject to DNA sequencing. In 14 infertile male patients with lowered LDH-C4 activity in sperms, it was identified a heterozygous T A mutation in base 115 of exon 5 of LDHC gene（GenBank accession number： GU479375）, changing codon 178 （TTG, encoding leucine） to a stop codon （TAG）. This nonsense mutation （L178X） was predicted to result in a severely truncated protein. The mutation and the heterozygosity were further confirmed by T-cloning. To the best of the knowledge, this is the first mutation found in human LDHC gene, substantiating that mutations in LDHC gene might cause male infertility.

关 键 词：不育症 睾丸特异性乳酸脱氢酶 乳酸脱氢酶C4 DHPLC 基因突变 

分 类 号：Q75[生物学—分子生物学] R394[医药卫生—医学遗传学]