The sex test provided in commercial PCR kits, such as the AmpFlSTR Profiler Plus is based on the amelogenin gene, which is located on the X chromosome and the Y chromosome. In the AmpFlSTR Profiler Plus system, absences of the Y copy will cause incorrect interpretation of gender based on this sex test alone, particularly if the source of the DNA is unknown as in forensic evidential samples. This study of 338 male individuals from 3 major ethnic groups in the Malaysian population showed a significant drop out of the amelogenin Y copy in a particular ethnic group and none in another group. Failure of the amelogenin test indicates the need for the inclusion of more reliable Y-loci in sex determination, as gender misidentification, at least in some populations, is going to have an unacceptable frequency if based on the amelogenin test alone. Although amelogenin failures are well reported, failure of this sex test at a frequency of 3.6 percent in the Malaysian Indians is high enough to be more than just noteworthy. As an alternative, the three Y-STR's appeared to be useful for gender verification, and the peculiar haplotype could provide extra assurance of a true null in the Indians. The Y-STR confirmation of male phenotype will be of relevance for forensic casework in prenatal sex tests, paternity cases, and in criminal investigations where the victim has identified the assailant as an Indian male but the crime scene samples obtained appear to show only a female DNA source. 3 tables, 2 figures, 17 references