Aase-Smith syndrome I: A syndrome of congenital malformations (birth defects) characterized by hydrocephalus, cleft palate, and severe arthrogryposis (joint contractures). Other anomalies may include deformed ears, ptosis (drooping) of the eyelids, inability to open the mouth fully, heart defects, and clubfoot. The fingers are thin with absent knuckles, reduced creases over the joints and inability to make a full fist.

The syndrome is inherited as an autosomal dominant trait, transmitted from generation to generation, affecting both males and females. It is named for the American dysmorphologists (birth-defect experts) Jon Aase and David W. Smith.