[Study on the mitochondrial DNA mutations in patients with early-onset diabetes mellitus].
OBJECTIVE
To investigate the prevalence of mitochondrial DNA (mtDNA) mutations in patients with early-onset diabetes in Tianjin, and to explore the relationship between mtDNA mutations and diabetes.


METHODS
348 non-related patients whose age at onset of diabetes was less than 45 years were randomly recruited, and 207 non-related and non-diabetic subjects were enrolled as controls. All their clinical and biochemical data were collected. Total genome was extracted conventionally from the participants' peripheral leucocytes, and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and cloning techniques were applied to the screening of mtDNA mutations (including the 3316, 3394 and 3426 in ND1 region, 12026 in ND4 region, and tRNA [Leu(UUR)] 3243 A-->G mutation).


RESULTS
The authors found 17 diabetics harboring the 12026 A-->G mutation in ND4 region (4.9%), 10 diabetics with mutations in ND1 region (including 5 diabetics with the 3394 T-->C mutation, 4 diabetics with 3316 G-->A mutation, one with 3426 A-->G mutation), and only two with the known 3243 A-->G mutation (0.6%). On the contrary, one control subject with the 3316 G-->A mutation, two with 3394 T-->C mutation and four with 12026 A-->G mutation were found. The prevalence of mtDNA mutations in the patient group is significantly higher than that in the control group (3.3%) (P<0.05).


CONCLUSIONS
The above findings suggest that mtDNA mutation may be implicated in the pathogenesis of the examined diabetes.
Yu
De-min
DM
Metabolic Disease Hospital, Tianjin Medical University, Tianjin, 300070 PR China.
Li
Ming-zhen
MZ
Liu
De-min
DM
D000328:Adult; D017668:Age of Onset; D002681:China / Q000453:epidemiology; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D003920:Diabetes Mellitus / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D005260:Female; D005787:Gene Frequency; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
D004272:DNA, Mitochondrial