Jacobsen syndrome (Q98025)

Jacobsen syndrome is a multiple congenital anomaly/mental retardation (MCA/MR) contiguous gene syndrome caused by partial deletion of the long arm of chromosome 11. The most common clinical features include pre- and postnatal growth retardation, psychomotor retardation, and a characteristic facial dysmorphism (skull deformities, hypertelorism, ptosis, coloboma, downslanting palpebral fissures, epicanthal folds, a broad nasal bridge, short nose, V-shaped mouth, and small, low-set and posteriorly rotated ears). Abnormal platelet function, thrombocytopenia or pancytopenia are usually present at birth. Patients commonly have malformations of the heart, kidney, gastrointestinal tract, genitalia, central nervous system and skeleton.