The mitochondrial A3243G mutation presenting as severe cardiomyopathy.
A 6 year old Portuguese boy with dilated cardiomyopathy had abundant ragged red fibres in muscle (20% of total) and severe lactic acidosis. Molecular genetic analysis showed the A to G transition in the mitochondrial transfer RNALeu(UUR) gene at nt 3243 ("MELAS mutation"), which accounted for 88% and 68% of the total mtDNA in his muscle and blood, respectively. Molecular studies in blood from 16 maternal relatives identified lower percentages of the mutation only in the oligo-symptomatic mother and brother. This case reinforces the notion that cardiomyopathy can be the presenting and predominant clinical expression of the A3243G mutation.
Vilarinho
L
L
Department of Clinical Biology, Instituto de Genética Médica, Porto, Portugal.
Santorelli
F M
FM
Rosas
M J
MJ
Tavares
C
C
Melo-Pires
M
M
DiMauro
S
S
D000140:Acidosis, Lactic / Q000235:genetics; D009202:Cardiomyopathies / Q000235:genetics*; D002648:Child; D004272:DNA, Mitochondrial / Q000235:genetics*; D006801:Humans; D017241:MELAS Syndrome / Q000235:genetics*; D008297:Male; D009132:Muscles / Q000473:pathology; D010375:Pedigree; D017354:Point Mutation; D012356:RNA, Transfer, Leu / Q000235:genetics
D004272:DNA, Mitochondrial; D012356:RNA, Transfer, Leu