Acrocephalosyndactyly

Aperts syndrome is characterized by agenesis or premature closure of the cranial sutures, midface hypoplasia and syndactyly of the hands and feet that is symmetrical and involves at least the second, third and fourth digits. An extensive midline calvarial defect is seen from the glabella to the posterior fontanelle, often producing a wide metopic suture area. Facial abnormalities include small orbits, ocular proptosis, small nasopharynx, and hypoplastic and retropositioned maxilla. Hand abnormalities include a short deviated thumb, complex osteocartilaginous syndactyly of the distal phalanges in the second, third and fourth digits, and simple syndactyly of the fourth and fifth digits. Three patterns of hand anomalies occur, sometimes referred to as spade hand, mitten hand and rosebud hand. Foot abnormalities include complete simple syndactyly and progressive osseous fusion of tarsal and metatarsal bones (Fig.1).

Hydrocephalus, corpus callosum and septal agenesis, septo-optic dysplasia, megencephaly, gyral abnormalities, encephalocoele, hypoplasia of white matter, and heterotopic grey matter also are seen.

Osseous fusions may also be evident in other joints of the extremities and in the spine. Cervical spine fusion is common and almost always involves C5 - C6.

Saethre - Chotzen syndrome is relatively common but of variable expression. Often the disease is mild. Craniosynostosis, low frontal hairline, ptosis, brachydactyly and cutaneous syndactyly of the fingers and of the second and third toes are characteristic features. Cranial abnormalities are variable.

Pfeiffers syndrome has three clinical subtypes and is manifested by craniosynostosis, broad thumbs and toes, variable maxillary retrusion and partial soft tissue syndactyly. Type I is classic Pfeiffer's syndrome; affected patients have normal intelligence and a good prognosis. Type II disease is associated with cloverleaf skull, severe proptosis and ankylosis of the elbows. Type III is manifested by the absence of cloverleaf skull but the presence of elbow ankylosis and a high morbidity in infancy. Additional features of Pfeiffer's syndrome are a hallux valgus deformity with a triangular proximal phalanx in the great toe and an enlarged first metatarsal bone. Cutaneous syndactyly of the second and third digits and shortening of the middle phalanges often are present in the hands and feet. Symphalangism of the thumb and other digits, carpal and tarsal fusions, and accessory epiphyses are among some additional malformations.

Jackson - Weiss syndrome is characterized by midface hypoplasia, craniosynostosis and anomalies of the feet (but usually normal hands). Numerous anomalies of the feet have been observed. The facial appearance in patients with the Jackson - Weiss syndrome has been likened to that in patients with Crouzon's syndrome, but marked proptosis is absent.

DR/RB