The thanatophoric dwarf. A report on two cases.

Two cases of thanatophoric dwarfism are presented. At external physical examination this anomaly is not readily distinguishable from achondroplasia and other forms of congenital disproportionate dwarfism. Radiologically, however, characteristic skeletal changes are demonstrable. The diagnosis can be made in utero. The clinical course is invariably fatal. The hereditary aspects, of importance for genetic counseling of parents, are still unexplained. The patients discussed show the typical thanatophoric skeletal changes in combination with a form of synostosis, i.e. bilateral radioulnar synostosis in one case, and synostosis of the coronal sutures and the lambdoid suture in the other. Emphasis is placed on the importance of radiological examination in cases of unexplained hydramnion and perinatal death.