A case of Amelogenin Y-null: a simple primer binding site mutation or unusual genetic anomaly?

A thirteen year old boy was murdered by a gunshot wound to the head. In order to confirm identity of the boy, samples were sent to the Instituto de Ciencias Forenses de Puerto Rico (PR-ICF) DNA laboratory. Autosomal DNA results exhibited only an X at the Amelogenin locus, whereas the autopsy results reported the child to be anatomically male. The sample was amplified with four separate YSTR marker systems. While a full Y-STR profile for the father of the boy was obtained, the boy only amplified at STR markers on the p arm of the Y chromosome. Theories that could account for this large absence of Y-STR results include an X-Y translocation or Yp isochromosome.