Congenital muscle fiber-type disproportion in a patient with congenital central hypoventilation syndrome due to PHOX2B mutations.

Increasing numbers of genetic origins are being reported for congenital muscle fiber-type disproportion. Most of these identified disorders are genetic myopathies. This is the first case report (to our knowledge) demonstrating congenital central hypoventilation syndrome due to PHOX2B mutations with congenital muscle fiber-type disproportion. The muscle histopathologic findings in the patient showed no changes of disuse atrophy and suggest that PHOX2B mutations may have an additional role in muscle development, contributing to respiratory failure in congenital central hypoventilation syndrome.