Greig Cephalopolysyndactyly Syndrome

Abstract

Greig cephalopolysyndactyly syndrome is characterized by macrocephaly with a broad and prominent forehead and polysyndactyly. Typical findings in the limbs are postaxial polydactyly of the hands (postaxial polydactyly type B, such as a small digit attached by a skin tag to the medial border of digit V) and preaxial polydactyly of the feet (duplication of the hallux). However, other combinations are possible with variable expressivity. The thumbs/halluces may be broad or partially duplicated. Postaxial polydactyly may be complete or more subtle, consisting of only a vestigial digit along the lateral aspect of the limb. Syndactyly primarily affects fingers III and IV but is variable, ranging from near complete webbing to fully separated digits. In the feet, toes I–III are most often affected. Syndactyly is usually cutaneous but may also be osseous. Craniofacial anomalies include high forehead and frontal bossing, macrocephaly, hypertelorism, and downward slanting palpebral fissures. Learning disabilities and absence or hypoplasia of the corpus callosum may be present. Mild degrees of hydrocephalus occur at low frequency.