title: Mutational analysis of whole mitochondrial DNA in patients with MELAS and MERRF diseases.
abstract: Mitochondrial diseases are clinically and genetically heterogeneous disorders, which make the exact diagnosis and classification difficult. The purpose of this study was to identify pathogenic mtDNA mutations in 61 Korean unrelated families (or isolated patients) with MELAS or MERRF. In particular, the mtDNA sequences were completely determined for 49 patients. From the mutational analysis of mtDNA obtained from blood, 5 confirmed pathogenic mutations were identified in 17 families, and 4 unreported pathogenically suspected mutations were identified in 4 families. The m.3243A>G in the tRNA(Leu(UUR))was predominantly observed in 10 MELAS families, and followed by m.8344A>G in the tRNA(Lys) of 4 MERRF families. Most pathogenic mutations showed heteroplasmy, and the rates were considerably different within the familial members. Patients with a higher rate of mutations showed a tendency of having more severe clinical phenotypes, but not in all cases. This study will be helpful for the molecular diagnosis of mitochondrial diseases, as well as establishment of mtDNA database in Koreans.
authors.affiliation: Department of Neurology, Ewha Womans University, School of Medicine, Ewha Medical Research Institute, Seoul, Korea.
authors.forename: Byung-Ok
authors.initials: BO
authors.lastname: Choi
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Hwang
authors.forename: Eun Min
authors.initials: EM
authors.lastname: Cho
authors.forename: Eun Hye
authors.initials: EH
authors.lastname: Jeong
authors.forename: Young Se
authors.initials: YS
authors.lastname: Hyun
authors.forename: Hyeon Jeong
authors.initials: HJ
authors.lastname: Jeon
authors.forename: Ki Min
authors.initials: KM
authors.lastname: Seong
authors.forename: Nam Soo
authors.initials: NS
authors.lastname: Cho
authors.forename: Ki Wha
authors.initials: KW
authors.lastname: Chung
mesh_terms: D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000032:analysis / Q000235:genetics*; D005260:Female; D006801:Humans; D017241:MELAS Syndrome / Q000175:diagnosis / Q000235:genetics*; D017243:MERRF Syndrome / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D017385:Sequence Homology; D055815:Young Adult
chemical_list: D004272:DNA, Mitochondrial