Congenital neuromuscular disease with type I fibre hypotrophy, ophthalmoplegia and myofibril degeneration.

We report a 7-year-old boy with progressive, early onset somatic and cranial muscle weakness associated with external ophthalmoplegia, facial weakness, type I fibre hypotrophy and myofibril degeneration. We separate this condition from congenital fibre type disproportion because of the facial weakness, ophthalmoplegia, central nucleation, and lysis in type I fibres. The case, which is similar to that described by Bender and Bender (1977), nosologically should be classified between the centronuclear myopathies and congenital fibre type disproportion, and most likely represents a congenital or neonatal disturbance of trophic interaction between nerve and muscle.