Genetic counseling: Acrofacial Dysostosis Syndrome

Acrofacial Dysostosis Syndrome

Definition

 * A condition resulting from problems in the development of the first & second branchial arches. The first arches produce the nerves and muscles for chewing, the lower jaw, 2 middle ear bones, and a small part of the ears. The second arches produce the nerves & muscles of facial expression, 1 middle ear bone, most of the external ears, and parts of the bone above the larynx.

Characteristics

 * underdevelopment of the cheek and jaw area (micrognathnia and malar hypoplasia)
 * feeding and breathing problems in infancy
 * down-sloping palpebral fissures
 * absence of the lower eyelashes
 * lack of development of the internal & external ear with temporary or long-term hearing loss
 * possible cleft palate
 * underdevelopment or absence of the thumb
 * shortened forearms & poor movement in the elbow/limited range of arm motion
 * stomach & kidney reflux
 * normal intellect
 * possible missing, overlapping, or webbing of the toes, clubfeet, hip dislocation, or underdeveloped ribs may occur

Incidence

 * very rare

Etiology

 * Unknown - may represent new mutations of an autosomal dominant trait or variable expression
 * Genetic testing is highly recommended

Genetics

 * located on chromosome 9q32

Prognosis

 * may be lethal is there is lung hypoplasia

Management

 * Possible need for a tracheostomy to help with breathing
 * Possible need for a gastrostomy tube to assure proper nutrition
 * craniofacial surgery to the jaw, cleft palate, & ears
 * plastic surgery for eye, jaw, ears
 * orthopedic surgery for arms, hands, feet, or toes
 * hearing screens
 * speech therapy for proper development
 * physical therapy to improve use of hands and feet

Differential Diagnosis

 * Miller Syndrome
 * Genee-Wiedemann Syndrome
 * Treacher Collins Syndrome
 * Pierre Robin Sequence
 * Franschetti-Klein Syndrome
 * Goldenhar-Gorlin Syndrome
 * Oral-Facial-Digital Syndrome
 * Juberg-Hayward Syndrome (Orocraniodigital Syndrome)
 * Hemifacial Microsomia (HFM)
 * Trisomy 18 (micrognathnia & distal ectromelia)