New mitochondrial DNA mutations in tRNA associated with three severe encephalopamyopathic phenotypes: neonatal, infantile, and childhood onset.
The reported cases showed clinical, biochemical, histopathological, and molecular features lending support to the hypothesis of a pathogenic effect of the detected mutations. Case 1 was a neonatal presentation who showed multiple mitochondrial respiratory chain enzyme defects in muscle associated with a new homoplasmic m.5514A > G transition in the tRNA(Trp) gene. Case 2 was a late infantile presentation who also showed mitochondrial respiratory chain enzyme deficiencies in muscle together with a new m.1643A > G tRNA(Val) mutation in homoplasmy. Case 3 showed a MERRF phenotype presented in childhood associated with the once previously reported m.15923A > G mutation in heteroplasmy in all the tissues studied.
Department of Pediatric Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, 08950 Esplugues, Barcelona, Spain. mocallaghan@hsjdbcn.org
María
M
del Mar O'Callaghan
Sonia
S
Emperador
Ester
E
López-Gallardo
Cristina
C
Jou
Nuria
N
Buján
Raquel
R
Montero
Angels
A
Garcia-Cazorla
Diana
D
Gonzaga
Isidre
I
Ferrer
Paz
P
Briones
Eduardo
E
Ruiz-Pesini
Mercè
M
Pineda
Rafael
R
Artuch
Julio
J
Montoya
D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D004272:DNA, Mitochondrial / Q000235:genetics*; D004579:Electron Transport; D006801:Humans; D007231:Infant, Newborn; D017243:MERRF Syndrome / Q000235:genetics*; D008928:Mitochondria / Q000378:metabolism; D028361:Mitochondrial Diseases / Q000235:genetics*; D008969:Molecular Sequence Data; D009132:Muscles / Q000473:pathology; D009154:Mutation; D009690:Nucleic Acid Conformation; D010641:Phenotype; D012343:RNA, Transfer / Q000235:genetics*
D004272:DNA, Mitochondrial; D012343:RNA, Transfer