Spinal muscular atrophy with congenital fractures: postmortem analysis.

We present a male infant with congenital fractures and features typical of spinal muscular atrophy. Mid-shaft fractures of the left humerus and both femurs occurred in utero. The patient died at 8 months of age following recurrent respiratory tract infections. His peripheral electrophysiologic studies were consistent with anterior horn cell disease. Molecular genetic studies were negative for the SMN gene. At autopsy, extensive anterior horn cell loss was present. There was extensive disease of skeletal muscle with relative sparing of the diaphragm. This patient represents a further case of this rare and fatal disease.