Congenital Fiber Type Disproportion Myopathy: A case report

ABSTRACT

Authors report a typical case of congenital fiber type disproportion (CFTD) with unique clinicopathologic characteristics. The patient was a 13-year-old boy who presented with weakness of lower extremities, especially proximal muscle, since his infancy. He has suffered from severe scoliosis which got worse since the age of 12. He showed mild dysarthria, high arched palate, and fish face. All routine laboratory data were within normal limits. EMG findings suggested myopathy. The muscle biopsy revealed fiber type disproportion with type 1 predominance. While most of the type 1 myofibers were atrophic or normal in size, the type 2 fibers showed universal hypertrophy. The difference of mean diameter between the larger and the smaller fibers was 27.9%. The patient's clinicopathologic settings fulfilled the criteria of CFTD.