A rare genetic disorder that results in mild to profound developmental delay. Four times more common in females. Most patients can be identified at birth by a hypoplastic fifth digit with absent or undeveloped nails, though all digits may be affected. Common facial abnormalities include coarse facies, broad nasal bridge and tip, a wide mouth with full, everted lips, bushy eyebrows, long eyelashes, abnormal ears, and an elongated philtrum. Typical presentation may also include hirsutism, microcephaly, joint laxity, intrauterine growth retardation, short stature, hearing loss, failure to thrive, respiratory infections, seizures, and sparse scalp hair along with a variety of cardiac, gastrointestinal, renal, and genitourinary anomalies.

Therapy is individualized to increase developmental outcomes, and some patients require surgery to correct abnormalities.