MT-ATP6 is associated with some cases of Leigh disease; clinical outcomes in our cohort ranged from death from neurodegenerative disease in early childhood to clinically and developmentally normal after several years of follow-up.
The result of mutational analysis revealed the absence of mitochondrial mutations in MT-ATP6 gene and the presence of a known homozygous splice site mutation c.516-517delAG in sibling patients added to the presence of a novel double het mutations in LS patient (c.752-18 A > C/c. c.751 + 16G > A).
Mutations in encoding genes of oxidative phosphorylation complexes have been frequently reported, of which, MTATP6 was one of the most frequently reported genes for Leigh syndrome.
Novel insights into the functional metabolic impact of an apparent de novo m.8993T>G variant in the MT-ATP6 gene associated with maternally inherited form of Leigh Syndrome.
Pathogenic mutations in MT-ATP6 are associated with the Leigh syndrome, the syndrome of neuropathy, ataxia, and retinitis pigmentosa (NARP), as well as with non-classical phenotypes, while MT-ATP8 is less frequently mutated in patients with mitochondrial disease.
Mutations in the human mitochondrial ATP6 gene encoding ATP synthase subunit a/6 (referred to as Atp6p in yeast) are at the base of neurodegenerative disorders like Neurogenic Ataxia and Retinitis Pigmentosa (NARP), Leigh syndrome (LS), Charcot-Marie-Tooth (CMT), and ataxia telangiectasia.
The MT-ATP6 m.9185T>C p.Leu220Pro mutation, previously associated with Leigh syndrome, was present in all family members, while the MT-TL1 m.3271T>C mutation, a known cause of MELAS syndrome, was observed in the sole patient with MELAS presentation.
The archetypal NARP syndrome is almost exclusively associated with the m.8993T>C/G mutation in the sixth subunit of the mitochondrial ATP synthase, whereas other mutations in the MT-ATP6 gene primarily associate with Leigh syndrome or Leber's hereditary optic neuropathy (LHON).
One patient was found to have Leigh syndrome due to a mutation in MT-ATP6, two affected siblings were discovered to be compound heterozygous for mutations in the NDUFV1 gene, which causes mitochondrial complex I deficiency, and one patient was found to have coenzyme Q10 deficiency due to compound heterozygous mutations in COQ2.
The rare T8993C mutation in the MT-ATP6 gene is generally considered to be clinically milder, but there is marked clinical heterogeneity ranging from asymptomatic carriers to fatal infantile Leigh syndrome.
The diagnosis of Leigh syndrome was subsequently confirmed by genetic study which showed a novel mutation at 8597T>C of the mitochondrial ATPase6 gene.
A T-to-C missense mutation at nucleotide position 9,185 in the protein-coding ATP6 gene of the mitochondrial genome was present at high heteroplasmy in members of a Canadian family with Leigh syndrome with predominant ataxia and peripheral neuropathy.
Following recent reports of this same mutation in a single case and in a family with late-onset LS and NARP-like features, our paper emphasises the role of MTATP6 in LS and expands the associated clinical phenotype further.
A T-to-C missense mutation at nucleotide position 9,185 in the protein-coding ATP6 gene of the mitochondrial genome was present at high heteroplasmy in members of a Canadian family with Leigh syndrome with predominant ataxia and peripheral neuropathy.