Clinical Characteristics

Craniofacial features include Pierre Robin Sequence or palatal anomalies, broad forehead with bitemporal narrowing, synophrys, flat midface with short anteverted nose, long philtrum, low-set posteriorly-rotated ears. Dental crowding and anterior open bite are observed in about half of affected individuals. Postnatal short stature is common, with some individuals exhibiting microcephaly and general growth failure. Skeletal anomalies are usually minor, including costovertebral malformations (11 pairs of ribs), sternal deformity, and phalangeal abnormalities including clinodactyly, and sandal gap. Bone age may be delayed. Congenital heart disease, including Ebstein’s anomaly and transposition of the great arteries, or arrhythmia warrant surveillance and long-term management. It is unclear if bone mineral density is affected in adults, but preliminary screening suggests that lumbar spine density may be reduced.