Handbook of 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)

References

• FACES: The National Craniofacial Association www.faces-cranio.org
• The Foundation for Nager and Miller Syndromes (FNMS) www.nagerormillersynd.com
• NORD www.rarediseases.org
• Gorlin's Syndromes of the Head and Neck p. 652-3

Notes

The information in this outline was last updated in 2001.