[A case of rigid spine syndrome with congenital cardiac abnormality of sinus venosus defect].

A 28-year-old male with a rigid spine syndrome who had congenital cardiac abnormality of sinus venosus defect was described. The patient was admitted to our hospital because of easy fatigability and palpitation. At the age of 4 years, he had an operation for his congenital cardiac abnormality and developed persistent atrial fibrillation thereafter. On neurological examination, he had average mentality, rigid spine with joint contractures, especially in the left elbow joint, and winged scapulae. He had marked muscle weakness and atrophy, predominantly in the left half of the extremities and trunk. Electromyographic studies demonstrated myopathic with partial neurogenic changes. Motor and sensory nerve conduction velocity was normal. A muscle biopsy specimen obtained from the right rectus femoris showed some marked hypertrophic and atrophic muscle fibers, with prominent internal nuclei, fiber splitting and pyknotic nuclear clump. ATP-ase stain showed type 2B fiber deficiency, increased number of type 2C fibers and fiber type grouping.