Jacobsen syndrome

With Jacobsen syndrome, which occurs in one of every 100,000 births, part of the long arm of chromosome 11 is missing. The typical features of the Jacobsen syndrome vary with regard to the severity of the condition. Characteristic are, however, anomalies of the head, eyes and face such as a triangle-shaped head, receding jaw, widely-spaced eyes, malformation of the iris and low-set ears. Most of the affected children are mildly to moderately intellectually challenged. The most common disorder is the limited or defective production of blood platelets and resultant increased bleeding tendency, which is present in 95 per cent of all cases. About 55 per cent of the children have congenital heart defects; in two-thirds of these cases the left ventricle is underdeveloped or missing. The prognosis is heavily dependant on the severity of the heart defect and the extent of the (blood) clotting disorder.

Author(s): Dr Stefanie Weismann-Günzler
Reviewed by: Dr Heide Seidel
Last updated: 2014-03-13