This condition is caused by a deletion in the short arm of chromosome 5 so that part of chromosone 5 is missing .The incidence is 1 in 50,000 births.
The characteristic clinical features are :
1.Rounded face with hypertelorism.
2.Characteristic cat-like cry of the child.This is due to the underdevelopment of larynx.
3.Mental retardation.
4.Micrognathia.
5.Congenital heart defects.
