[Abnormalities-retardation syndrome caused by incomplete triploidy].

We report on a four year old boy with multiple congenital anomalies and mental retardation due to incomplete triploidy (diploid triploid mixoploidy). Initially, we had thought of the Silver-Russell syndrome. The main characteristics in the patient are short stature, body asymmetry, hypogenitalism, and considerable mental retardation. In addition, there are several minor anomalies of the hands and feet. The diagnosis was verified by microscopic detection of a triploid cell line in cultivated skin fibroblasts and by supplementary studies using flow cytometry. The characteristics of this recognizable multiple congenital anomalies/mental retardation syndrome are discussed with reference to the pertinent literature. As differential diagnosis, in particular the Silver-Russell syndrome has to be taken into account.