Larsen's syndrome with novel congenital anomalies.

A full-term female infant with the rare Larsen's syndrome who died after 2 days is presented. The infant exhibited several of the anomalies characteristically reported with this syndrome. These include multiple joint deformities, a flattened facies, hydrocephalus, cardiac defects, and tracheal stenosis. We now report two additional congenital malformations that have not been previously reported with this syndrome: complete agenesis of the anus, with the distal colon ending in a cul-de-sac, and the presence of a bifid uterus. These novel congenital anomalies further support the etiology of Larsen's syndrome as a generalized mesenchymal disorder, since they arise from a defective process of embryonal induction involving mesenchymal tissue.