Synonym: bird-headed dwarf, microcephalic midget
Genetic loci affected
(1) 3q22.1-q24 OR
(2) 18p11.31-q11.2
Primary clinical features:
(1) microcephaly
(2) severe short stature
(3) large, beak-like nose
Additional findings:
(1) intra-uterine growth retardation
(2) mental retardation
(3) micrognathia
(4) low-set, malformed ears
(5) downward slanting palpebral fissures
(6) clinodactyly of the fifth finger
(7) simian crease
(8) hypoplasia of the proximal radius, with dislocation at the elbow
(9) dislocation of the hip
(10) hypoplasia of the proximal fibula
(11) cryptorchidism in males
(12) 11 pairs of ribs (rather than 12)
(13) hyperactive
(14) scoliosis and/or kyphosis
