Long survival in patients with leigh syndrome and the m.10191T>C mutation in MT-ND3 : a case report and review of the literature

Abstract

We report an unusual case of Leigh syndrome due to the m.10191T>C mutation in the complex I gene MT-ND3. This mutation has been associated with a spectrum of clinical phenotypes ranging from infant lethality to adult onset. Despite infantile onset and severe symptoms, our patient has survived to early adulthood because of a strict dietary regimen and parental care. This patient is an extreme example of the frequently prolonged course of Leigh syndrome due to this particular mutation.

Keywords: Leigh syndrome; ND3; complex I deficiency; m.10191T>C; mitochondria.

Figure 1

Direct sequence electropherogram of the m.10191T>C mutation. Note the high mutation load as seen by the blue C signal instead of red T signal in the urine and blood of the proband and lesser degree of heteroplasmy in her unaffected mother, compared to control blood.

Figure 2

Polymerase chain reaction–restriction fragment length polymorphism analysis of the m.10191T>C mutation using a mismatch primer. The mutant sequence introduces an RsaI site yielding additional 118 bp fragment, whereas the wild-type sequence lacks the RsaI site and yields only a 147 bp fragment. Heteroplasmy levels are listed in Table 2.