Partial trisomy 10p.

It is reported on a boy of 4 years 9 months with trisomy of the distal part of the short arm of a chromosome 10, due to a balanced 7/10 translocation in the father. Besides multiple minor dysmorphias the patient showed severe mental retardation, small stature, hypotonia, retarded bone age. The high and bulky forehead was especially remarkable, because this sign has also been noted in formerly reported cases with trisomy 10p.