De novo (11;13) translocation.

A male infant is described with unusual facial appearance, clubfeet, and moderate hydrocephalus internus without obvious deficiency in mental and physical development. Cytogenetic studies revealed a karyotype of 45,XY,--C,--D,+t(C;D). A chromosome 11 and a 13 are involved in the formation of the translocation chromosome. The long arm of chromosome 13 is linearly attached to the end of the long arm of chromosome 11 (tandem translocation). Chromosome material of the distal part of the long arm of chromosome 11, as well as the short arm plus the centromere of chromosome 13 seem to have been lost.