Trisomy 9 mosaicism is rare.
Diagnosis requires presence of normal karyotype and trisomy 9.
Facial features:
(1) low-set ears with posterior rotation
(2) receding jaw, micrognathia
(3) high-arched palate
(4) microcephaly
(5) occipital bossing
(6) bilateral ptosis
(7) broad nose with bulbous tip
(8) hypertelorism
(9) short or webbed neck
Other findings:
(1) mental retardation
(2) short stature
(3) hypotonia
(4) cardiac anomalies
(5) hydrocephalus
(6) simian crease
(7) joint dislocations
(8) cryptorchidism in males
