Asymmetric arthrogryposis multiplex congenita with focal pachygyria.

A male infant with predominantly right-sided arthrogryposis multiplex congenita is presented. His posture in the lower extremities was asymmetric, and left thoracic scoliosis was present. This patient also manifested focal pachygyria dominantly affecting the contralateral cerebral hemisphere and hypoplasia of the corpus callosum, brainstem, and cerebellar vermis. Generalized tonic seizures began at 2 months of age, and an electroencephalogram revealed epileptic discharge. Biopsy of the right biceps revealed a nonspecific change. A direct causal relationship between neuronal migration disorders and arthrogryposis multiplex congenita has not been established, but considering the abnormal neuronal migration along the entire neural axis in focal pachygyria, the predominantly right-sided arthrogryposis in this patient was speculated to be closely related to the pachygyria of the frontal and temporal lobes dominantly affected in the left cerebral hemisphere.