Extra Yq and partial monosomy 12p due to a Y;12 translocation in a boy with features of the 12p deletion syndrome.

A Y;12 translocation, resulting in extra Yq material and partial monosomy 12p, was found in a 7 1/2 year old boy. He showed growth and mental retardation and several of the congenital anomalies seen in the 12p deletion syndrome. LDHB activity, the gene for which is located at 12p12, was normal in serum, in accordance with the suspected 12p13 deletion in the patient.