Arhinencephaly. The spectrum of associated malformations.

Eight cases are presented of arhinencephaly and its associated malformations, which included 2 examples of holoprosencephaly and 3 of agenesis of the corpus callosum. Additional features included cortical malformations, anomalies of the long tracts and of the optic pathway, cerebellar hypoplasia and dentato-olivary dysplasia. Each of these components covered a wide spectrum ranging in severity from extreme to minimal. Craniofacial dysmorphism, and cardiac, renal and endocrine disorders were present in some cases. Only 2 cases were associated with chromosomal abnormalities, 1 with trisomy 13, the other with partial trisomy 7(7q+). Of possible environmental factors, maternal diabetes was recorded in 1 case. While all cases can be classified into broad categories, the individual variations render each case apparently unique.