Congenital myopathy with progressive external ophthalmoplegia.

Progressive external ophthalmoplegia is associated with an increasingly heterogeneous group of neuromuscular disorders. We describe a 16-year-old girl with delayed motor milestones and onset of progressive external ophthalmoplegia at age 3 years and proximal muscle weakness at age 10 years. Muscle biopsy specimen demonstrated type I myofiber predominance and type II myofiber atrophy. Although the pathological features of this congenital myopathy are quite nonspecific, the case further illustrates the pathogenetic heterogeneity of the progressive external ophthalmoplegia phenotype.