[Case of partial trisomy 4p+ in a child as a result of a balanced translocation in the father].

Clinical and cytogenetic data on the infant with mental retardation, multiple congenital anomalies and trisomy for the short arm of the 4th chromosome (46, XY, der (1) (1;4) (q43; p15) are given. The abnormal chromosome was inherited from the father who had a balanced translocation 46, X; (1, 4) (q43; p15). Clinical features of the patient corresponded to those in the observation of other authors.