Brief clinical reports: aprosencephaly-atelencephaly and the aprosencephaly (XK) syndrome.

We report on a postnatally dead, postterm male infant with aprosencephaly and the oculofacial manifestations usually seen in the most severe form of alobar holoprosencephaly -- namely cyclopia and absence of derivatives of the frontonasal process; in addition the infant had the radius aplasia field defect bilaterally, a high VSD, mobile cecum, and penile hypospadias with cryptorchidism. The same syndrome was reported recently by Garcia and Duncan [2]; however, in that case the brain defect was designated "atelencephaly." Since atelencephaly is a less severe form of aprosencephaly we chose to designate the condition in these two patients as "the aprosencephaly (XK) syndrome." Atelencephaly and aprosencephaly may occur also as a single and sporadic malformation. The cause of the aprosencephaly (XK) syndrome is unknown.