The acrocallosal syndrome in first cousins: widening of the spectrum of clinical features and further support for autosomal recessive inheritance.

First cousins, related through their mothers, showed a pattern of craniofacial, brain, and limb anomalies consistent with the acrocallosal syndrome. Both patients had a defect of the corpus callosum, macrocephaly with a protruding forehead and occiput, hypertelorism, non-horizontal palpebral fissures, a small nose, notched ear lobes, and postaxial polydactyly of the hands. The boy, in addition, had hypospadias, cryptorchidism, inguinal hernias, duplication with syndactyly of the phalanges of the big toe, and a bipartite right clavicle. The girl had an arachnoidal cyst, a calvarian defect, and digitalisation of the thumbs. Motor and mental development was retarded in both patients. This observation provides further evidence of probable autosomal recessive inheritance of the acrocallosal syndrome and widens the spectrum of clinical findings and the variability of features in this rare malformation syndrome.