Identification of novel mutations in five patients with mitochondrial encephalomyopathy.
MELAS, MERRF, LHON and NARP, are well-established mitochondrial syndromes associated with specific point mutations of mitochondrial DNA (mtDNA). However, these recurrent mtDNA mutations account for only a minority of mitochondrial disease cases. To evaluate the impact of novel mtDNA mutations, we performed mtDNA sequence analysis in muscle and other tissues of 240 patients with different mitochondrial neuromuscular syndromes. We identified a total of 33 subjects with novel, private or uncommon mutations. Among these, five novel mutations were found in both paediatric and adult cases. We here report on the clinical description of these patients, as well as the biochemical and molecular genetic characterization of the corresponding mutations. Patients 1 and 2 showed changes in ND genes, patient 3 carried a heteroplasmic deletion in the COI gene, patients 4 and 5 carried heteroplasmic mutations in tRNA(Trp) and tRNA(Phe), respectively. Altogether, these data indicate that mtDNA analysis must become part of the routine screening for mitochondrial disorders.
Valente
Lucia
L
IRCCS Foundation Neurological Institute C. Besta, Milan, Italy.
Piga
Daniela
D
Lamantea
Eleonora
E
Carrara
Franco
F
Uziel
Graziella
G
Cudia
Paola
P
Zani
Anna
A
Farina
Laura
L
Morandi
Lucia
L
Mora
Marina
M
Spinazzola
Antonella
A
Zeviani
Massimo
M
Tiranti
Valeria
V
D000328:Adult; D001921:Brain / Q000473:pathology; D002648:Child; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008931:Mitochondria, Muscle / Q000235:genetics / Q000473:pathology; D017237:Mitochondrial Encephalomyopathies / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology; D009154:Mutation; D009245:NADH Dehydrogenase / Q000235:genetics; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D013385:Succinate Dehydrogenase / Q000235:genetics
D017931:DNA Primers; D004272:DNA, Mitochondrial; D004247:DNA; D013385:Succinate Dehydrogenase; D009245:NADH Dehydrogenase; D003576:Electron Transport Complex IV