Nemaline myopathy: description of an adult onset case.

Nemaline myopathy is a rare congenital muscle disease, with neonatal or adult onset. We report clinical and ultrastructural study of a 73-year-old woman whose symptoms manifested at age 40 years with proximal muscle weakness, nocturnal cramps, muscle pain and walking impairment. Muscle biopsy showed rods and other typical findings suggesting nemaline myopathy. This myopathy should be taken into account in the differential diagnosis of adult onset myopathies. Only ultrastructural examination allows an exact diagnosis.