Mitochondrial DNA sequence analysis in congenital myotonic dystrophy.

Mitochondrial genetic modifying factors have been suspected in several autosomally inherited diseases. The congenital variant of myotonic dystrophy, in which there is striking maternal inheritance pattern, is a likely candidate disease. To investigate this possibility, we sequenced completely the mitochondrial genome in 2 patients with congenital myotonic dystrophy. Comparison of the two sequences with control data failed to reveal a specific nucleotide variant or length variant in this disease. We conclude that a mitochondrial genetic modifying factor is not present in congenital myotonic dystrophy.