Maternally transmitted diabetes mellitus associated with the mitochondrial tRNA(Leu(UUR)) A3243G mutation in a four-generation Han Chinese family.
We report here the characterization of a four-generation Han Chinese family with maternally transmitted diabetes mellitus. Six (two males/four females) of eight matrilineal relatives in this family exhibited diabetes. The age of onset in diabetes varies from 15 years to 33 years, with an average of 26 years. Two of affected matrilineal relatives also exhibited hearing impairment. Molecular analysis of mitochondrial DNA (mtDNA) showed the presence of heteroplasmic tRNA(Lue(UUR)) A3243G mutation, ranging from 35% to 58% of mutations in blood cells of matrilineal relatives. The levels of heteroplasmic A3243G mutation seem to be correlated with the severity and age-at-onset of diabetes in this family. Sequence analysis of the complete mitochondrial genome in this pedigree revealed the presence of the A3243G mutation and 38 other variants belonging to the Eastern Asian haplogroup M7C. However, none of other mtDNA variants are evolutionarily conserved and implicated to have significantly functional consequence. Thus, the A3243G mutation is the sole pathogenic mtDNA mutation associated with diabetes in this Chinese family.
Lu
Jianxin
J
Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China.
Wang
Dawang
D
Li
Ronghua
R
Li
Weixing
W
Ji
Jingzhang
J
Zhao
Jing
J
Ye
Wei
W
Yang
Li
L
Qian
Yaping
Y
Zhu
Yi
Y
Guan
Min-Xin
MX
D000293:Adolescent; D000328:Adult; D002681:China; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000032:analysis / Q000235:genetics; D048909:Diabetes Complications / Q000235:genetics; D003920:Diabetes Mellitus / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D012356:RNA, Transfer, Leu / Q000235:genetics*
D004272:DNA, Mitochondrial; D012356:RNA, Transfer, Leu