Mitochondrial genetic analysis in a Chinese family suffering from both mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes and diabetes.
To investigate the mitochondrial mutations in patients suffering from both mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) and maternally inherited diabetes. MELAS was confirmed by muscle biopsy performed from the biceps muscle of the proband. Mitochondrial DNA (mtDNA) was isolated from peripheral blood mononuclear cells. The significant mtDNA loci of other 14 family members were further detected according to the sequencing results of the proband. Direct sequencing of PCR products was used to identify the mitochondrial mutations. The proband (III 1) and her brother (III 3) both harbored the tRNALeu (UUR) A3243G mutation, with heteroplasmic levels of 50% and 33% respectively. Moreover, another two mitochondrial variants, A8860G and A15326G, were also detected in the samples of all the family members. MELAS and diabetes can coexist in one patient, and the main cause for these diseases is the tRNALeu (UUR) A3243G mutation. However, other gene variants may contribute to its pathogenesis. This case also supports the concept that both syndromes can be regarded as two phenotypes of the same disease.
Department of Endocrinology, Qianfoshan Hospital, Shandong University 66 Jingshi Road, Jinan 250014, China.
Weiwei
W
Li
Department of Endocrinology, Qianfoshan Hospital, Shandong University 66 Jingshi Road, Jinan 250014, China.
Wei
W
Zhang
Department of Endocrinology, Qianfoshan Hospital, Shandong University 66 Jingshi Road, Jinan 250014, China.
Fang
F
Li
Department of Endocrinology, Qianfoshan Hospital, Shandong University 66 Jingshi Road, Jinan 250014, China.
Cailing
C
Wang
D000328:Adult; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D001706:Biopsy; D002681:China; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D040941:Heredity; D006801:Humans; D017241:MELAS Syndrome / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012356:RNA, Transfer, Leu / Q000235:genetics*; D055815:Young Adult
D004272:DNA, Mitochondrial; D012356:RNA, Transfer, Leu
A3243G mutation; Diabetes; MELAS; heteroplasmy; mitochondrial myopathy; polymorphism