Multiple mitochondrial tRNA(Leu[UUR]) mutations associated with infantile myopathy.
We have identified a cluster of mitochondrial tRNA(Leu[UUR]), mutations in a severe case of infantile myopathy. There were A to G transitions found at mtDNA positions 3259, 3261, 3266 and 3268. These point mutations change the anticodon arm and the anticodon UAA, normally found in tRNA(Leu[UUR]), to UGA which is the one of the tRNAs(Ser[UCN]). This is the first anticodon alteration described in this tRNA. Another swap straight to the anticodon of tRNA(Pro) alone was recently described in a less severe case. Until now infantile myopathies have not been attributed to defined mtDNA alterations. This study reports for the first time mtDNA point mutations causing this early onset of a mitochondrial disorder. The apparent homoplasmy of these mutations and especially the location in the anticodon must be considered lethal, if the child would not have been respirated for 5 years from its birth.
Zanssen
S
S
Institut für Biochemie, Medizinische Fakultät, RWTH Aachen, Germany.
Molnar
M
M
Schröder
J M
JM
Buse
G
G
D000818:Animals; D001483:Base Sequence; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008931:Mitochondria, Muscle / Q000235:genetics*; D017240:Mitochondrial Myopathies / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D012313:RNA / Q000235:genetics*; D000077278:RNA, Mitochondrial; D012356:RNA, Transfer, Leu / Q000235:genetics*; D016415:Sequence Alignment
D000077278:RNA, Mitochondrial; D012356:RNA, Transfer, Leu; D012313:RNA