Pena-Shokeir I syndrome: a comparative pathological study.

A case of Pena-Shokeir I syndrome in a female neonate is reported. The baby died of respiratory insufficiency shortly after birth. Postmortem examination revealed marked pulmonary hypoplasia and microscopic abnormalities of the hypoglossal nucleus and anterior horn cells in spinal cord. A comparative study with respect to hypoglossal nucleus disclosed the possibility of hypoplasia of the hypoglossal nucleus as part of this syndrome. This finding led us to propose that hypoplasia of the nucleus is one of the causes of polyhydramnios, based on the lack of swallowing activity. Moreover, ectopic cross-striated muscle fibers and an increase of muscle spindles were noted in tongue. The findings, particularly the neuropathologic one, provide further insight into the pathogenesis of the syndrome.