Analysis of mitochondrial gene mutations in Chinese pedigrees of Leber's hereditary optic neuropathy

To investigate the frequency of common pathogenic primary mitochondrial DNA mutations in Leber's hereditary optic neuropathy (LHON) families.

Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing were used to detect mitochondrial DNA mutations. Sixty-six Chinese examiners from 15 families, including 22 visual affected and their 44 unaffected maternal relatives, underwent molecular genetic evaluation. Eleven normal individuals underwent evaluation as control.

Of the 15 families with suspicion of LHON, 13 had nucleotide position (nt) G11778A mutations, 2 had nt T14484C mutations. All examiners had nt G11719A mutations.

The mutations at nucleotides 11778 and 14484 are primary LHON mutations. Molecular genetic findings suggest that the silent mutation at nt G11719A may be a common genetic polymorphism in Chinese.