Aase-Smith Syndrome

Hydrocephalus (Dandy-Walker anomaly), cleft palate, severe joint contractures, congenital neuroblastoma, ventricular septal defects.

Distal Arthrogryposis Type IIB Syndrome; Triphalangeal Thumb-Hypoplastic Anemia Hydrocephalus Syndrome.

First described in 1968, in a father and two children, by Jon Morton Aase and David Weyhe Smith, American pediatricians.

Autosomal dominant.

Based on the clinical findings of severe joint contractures and joint anomalies, and hydrocephalus with Dandy-Walker anomaly.

Cranial features may include hydrocephalus associated with a Dandy-Walker malformation, ptosis, external ear deformities, and limited mouth opening. Multiple ventricular septal defects have been reported. Severe joint contractures affect predominantly the fingers. Very thin and filiform fingers with absent knuckles. Limited extension of the elbows and knees. Clubfoot deformity. Congenital neuroblastoma has been reported.

Obtain an echocardiogram to rule out cardiac lesions. Check for the presence of raised intracranial pressure (check fontanelle in infants). Ultrasound may be required to rule out neuroblastoma.

Very severe limitation of mouth opening. Expect airway management to be difficult. Maintain spontaneous ventilation until the airway has been secured. Careful positioning and padding are essential.

Avoid neuromuscular blockers until the airway has been secured.