The phenotype of a 45,X male with a Y/18 translocation.

In this report, we describe a male infant with a 45,X karyotype; the entire short arm and the centromere of the Y chromosome were translocated onto the short arm of chromosome 18, resulting in an unbalanced dicentric chromosome. Breakpoints were identified by in situ fluorescence hybridization (FISH) on the proximal Yq11 and 18p11.2. Both Y and 18 centromeric alphoid sequences were identified on the derived 18 chromosome. Clinical features were compatible with 18p- syndrome and no Turner stigmata were present in our propositus. Short stature was likely to be related to the deletion of 18p and/or Yq, where a gene involved in stature determination has been located proximal to a gene involved in spermatogenesis (AZF).