The m.8993T>G mutation of the mitochondrial MT-ATP6 gene has been associated with numerous cases of neuropathy, ataxia, and retinitis pigmentosa (NARP) and maternally inherited Leigh Syndrome (MILS), which are diseases known to result from abnormalities affecting mitochondrial energy production.
A mutation (m.9176 T > G) of the mitochondrial ATP6 gene that replaces an universally conserved leucine residue into arginine at amino acid position 217 of human subunit a (aL<sub>217</sub>R) has been associated to NARP (Neuropathy, Ataxia and Retinitis Pigmentosa) and MILS (Maternally Inherited Leigh's Syndrome) diseases.
Mutations in the mitochondrial DNA (mtDNA) encoded subunit 6 of ATPase (ATP6) are associated with variable disease expression, ranging from adult onset neuropathy, ataxia and retinitis pigmentosa (NARP) to fatal childhood maternally inherited Leigh's syndrome (MILS).
The present report describes a Tunisian family with a maternally inherited Leigh syndrome harboring the mitochondrial T8993G mutation in the ATPase 6 gene.
The molecular pathogenic mechanism of the human mitochondrial diseases neurogenic ataxia and retinitis pigmentosa and maternally inherited Leigh syndrome was determined in cultured human cells harboring homoplasmic T8993G/T8993C point mutations in the mitochondrial ATP6 gene, which encodes subunit 6 of the F1F0-ATP synthase.