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 e ntire short arm and the centromere of the Y chromosome were translocat ed onto the short arm of chromosome 18, resulting in an unbalanced dic entric 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 chromo some, Clinical features were compatible with 18p- syndrome and no Turn er stigmata were present in our propositus. Short stature was likely t o be related to the deletion of 18p and/or Yq, where a gene involved i n stature determination has been located proximal to a gene involved i n spermatogenesis (AZF).