[Leigh syndrome resulting from a de novo mitochondrial DNA mutation (T8993G)].
BACKGROUND
Several degenerative neurological diseases are caused by mutations in the mitochondrial gene coding for subunit 6 of the ATPase. Thus, NARP (neurogenic weakness, ataxia, and retinitis pigmentosa) and Leigh syndromes are associated to a T8993G mutation when the percentage of mutant mitochondrial DNA is low (60 90%) or high (>90%), respectively. Leigh syndrome is also caused by a second mutation in the same position T8993C.


METHODS
The patient, a boy that died at 6 months, had generalized hypotonia, psychomotor delay, hepatomegaly, choreic movements and hyporreflexia. MRI showed hypodensities in the basal ganglia and brain stem as well as hyperlactacidemia. Molecular genetic analysis of the mitochondrial DNA showed that the patient had the T8993G mutation in a percentage higher than 95%. No mutated DNA was detected in blood of the proband s mother, maternal aunt and grandmother.


CONCLUSIONS
The point mutation T8993G may occur de novo, at high levels, causing neurodegenerative diseases.
Departamento de Bioquímica y Biología Molecular y Celular; Universidad de Zaragoza, Zaragoza, España.
A
A
Playán
A
A
Solano-Palacios
J B
JB
González de la Rosa
J M
JM
Merino-Arribas
A L
AL
Andreu
M
M
López-Pérez
J
J
Montoya
D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D007888:Leigh Disease / Q000235:genetics*; D008297:Male; D025261:Mitochondrial Proton-Translocating ATPases / Q000235:genetics*; D017354:Point Mutation
D004272:DNA, Mitochondrial; C412204:ATP synthase subunit 6; D025261:Mitochondrial Proton-Translocating ATPases