A new sequence variant in mitochondrial DNA associated with high penetrance of Russian Leber hereditary optic neuropathy.

We have analyzed mitochondrial DNA sequence in 15 Russian LHON patients and found the new mtDNA sequence variant in one family (2 patients) who showed 100% penetrance of the disease in men. This family has a T14484C primary mutation, and four secondary mutations (T4216C, G13708A, G15812A, G15257A), which belong to the European haplogroup J. The new sequence variant of A9016G in the ATPase 6 gene changed highly conserved amino acid of isoleucine to valine, has not been found in the rest of 13 LHON patients and controls. This novel sequence variant may contribute to the 100% penetration of LHON disorder in men of this family.