Lattanzi et al. (2005) found a large interstitial deletion of the Y short arm encompassing the AMELY locus in 2 unrelated individuals. One case was identified from a sample of 493 infertile males; the other arose from studies ... Lattanzi et al. (2005) found a large interstitial deletion of the Y short arm encompassing the AMELY locus in 2 unrelated individuals. One case was identified from a sample of 493 infertile males; the other arose from studies done on 13,000 unselected amniotic fluid samples from male fetus pregnancies (indicating an overall prevalence of 0.008%). Lattanzi et al. (2005) commented that even though the frequency of the amelogenin deletion is low, conclusions about gender should not be drawn based on amelogenin alone in situations involving prenatal diagnosis, paternity testing, or criminal investigation. Using a combination of STS deletion mapping, binary marker and Y-short tandem repeat haplotyping, and TSPY (480100) copy number estimation, Jobling et al. (2007) identified 4 distinct classes of deletions affecting chromosome Yp in 45 males from 12 different populations. The most common deletion class was found in 41 Y chromosomes (91%) and appeared to be caused by nonallelic homologous recombination between the major TSPY repeat array and a single telomeric copy of the TSPY gene located over 3 Mb from the array. This deletion resulted in loss of the AMELY, TBL1Y (400033), and PRKY (400008) genes, which lie in the region separating the single TSPY gene and the TSPY repeat array, as well as reduced TSPY copy number. The rarer deletion classes did not involve the major TSPY repeat array, but resulted in loss of the more telomeric PCDH11Y gene (400022) in addition to AMELY, TBL1Y, PRKY, and the single telomeric TSPY copy. The persistence and expansion of deletion lineages, together with phenotypic evidence, suggested that absence of these genes has no major deleterious effects.