title: Mitochondrial gene mutations in the tRNA(Leu(UUR)) region and diabetes: prevalence and clinical phenotypes in Japan.
abstract: BACKGROUND
  Mitochondrial gene mutations play a role in the development of diabetes mellitus. We have assessed the frequency of the A3243G and other mitochondrial mutations in Japan and in the relationship to clinical features of diabetes.
  
  
  METHODS
  DNA was obtained from peripheral leukocytes of 240 patients with diabetes mellitus (39 with type 1; 188 with type 2; 13 with gestational diabetes) and 125 control subjects. We used PCR-restriction fragment length polymorphism analysis (ApaI) for A3243G and PCR-single-strand conformation polymorphism analysis to determine the mutations in the mitochondrial gene including nucleotide position 3243.
  
  
  RESULTS
  The A3243G mutation was found in seven patients, and an inverse relationship was observed between the degree of heteroplasmy and the age at onset of diabetes. A3156G, G3357A, C3375A, and T3394C were detected in addition. Those who shared the same mutation showed similar clinical characteristics, thus representing a putative clinical subtype. The patients with A3156G had a sudden onset of hyperglycemia and showed a rapid progression to an insulin-dependent state with positive anti-glutamic acid decarboxylase antibody. Those with T3394C showed a mild defect in glucose-stimulated insulin secretion, and hyperglycemia appeared after adding such factors as aging or obesity.
  
  
  CONCLUSIONS
  The identification of mitochondrial gene mutations allows preclinical diagnosis of diabetes and prediction of the age at onset by evaluating the degree of heteroplasmy in cases with A3243G. Mutation detection may also be important for patient management and identification of affected family members.
authors.affiliation: Department of Laboratory Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan. kokubo@cis.fukuoka-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Ohkubo
authors.forename: A
authors.initials: A
authors.lastname: Yamano
authors.forename: M
authors.initials: M
authors.lastname: Nagashima
authors.forename: Y
authors.initials: Y
authors.lastname: Mori
authors.forename: K
authors.initials: K
authors.lastname: Anzai
authors.forename: Y
authors.initials: Y
authors.lastname: Akehi
authors.forename: R
authors.initials: R
authors.lastname: Nomiyama
authors.forename: T
authors.initials: T
authors.lastname: Asano
authors.forename: A
authors.initials: A
authors.lastname: Urae
authors.forename: J
authors.initials: J
authors.lastname: Ono
mesh_terms: D000328:Adult; D004272:DNA, Mitochondrial / Q000235:genetics*; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D018807:Polymorphism, Single-Stranded Conformational; D015995:Prevalence; D012356:RNA, Transfer, Leu / Q000235:genetics*; D012680:Sensitivity and Specificity
chemical_list: D004272:DNA, Mitochondrial; D012356:RNA, Transfer, Leu