title: Mitochondrial DNA 3644T-->C mutation associated with bipolar disorder.
abstract: Mitochondrial dysfunction associated with mutant mitochondrial DNA (mtDNA) has been suggested in bipolar disorder, and comorbidity with neurodegenerative diseases was often noted. We examined the entire sequence of mtDNA in six subjects with bipolar disorder having comorbid somatic symptoms suggestive of mitochondrial disorders and found several uncharacterized homoplasmic nonsynonymous nucleotide substitutions of mtDNA. Of these, 3644C was found in 5 of 199 patients with bipolar disorder but in none of 258 controls (p = 0.015). The association was significant in the extended samples [bipolar disorder, 9/630 (1.43%); controls, 1/734 (0.14%); p = 0.007]. On the other hand, only 5 of 25 family members with this mutation developed bipolar disorder, of which 4 patients with 3644C had comorbid physical symptoms. The 3644T-->C mutation converts amino acid 113, valine, to alanine in the NADH-ubiquinone dehydrogenase subunit I, a subunit of complex I, and 113 valine is well conserved from Drosophila to 61 mammalian species. Using transmitochondrial cybrids, 3644T-->C was shown to decrease mitochondrial membrane potential and complex I activity compared with haplogroup-matched controls. According to human mitochondrial genome polymorphism databases, 3644C was not found in centenarians but was found in 3% of patients with Alzheimer disease and 2% with Parkinson disease. The result of modest functional impairment caused by 3644T-->C suggests that this mutation could increase the risk for bipolar disorder.
authors.affiliation: Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Hirosawa 2-1, Wako, Saitama 351-0198, Japan.
authors.forename: Kae
authors.initials: K
authors.lastname: Munakata
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Kanako
authors.initials: K
authors.lastname: Mori
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Washizuka
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoneda
authors.forename: Osamu
authors.initials: O
authors.lastname: Tajima
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Akiyama
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nanko
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kunugi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tadokoro
authors.forename: Norio
authors.initials: N
authors.lastname: Ozaki
authors.forename: Toshiya
authors.initials: T
authors.lastname: Inada
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Takako
authors.initials: T
authors.lastname: Fukunaga
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Iijima
authors.forename: Nakao
authors.initials: N
authors.lastname: Iwata
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tatsumi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamada
authors.forename: Takeo
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Tadafumi
authors.initials: T
authors.lastname: Kato
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics*; D016022:Case-Control Studies; D004272:DNA, Mitochondrial / Q000235:genetics*; D042967:Electron Transport Complex I / Q000378:metabolism; D005260:Female; D006801:Humans; D006822:Hybrid Cells / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008564:Membrane Potentials; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D010375:Pedigree
chemical_list: D004272:DNA, Mitochondrial; D042967:Electron Transport Complex I