A rare mutation in the amelogenin gene and its potential investigative ramifications

Over the past few years, the Australian forensic science community has adopted a common methodology and technology in the application of DNA profiling for investigative and forensic purposes. The ultimate objective of this initiative is the establishment of a national DNA database similar to that used in the UK. An integral part of this methodology is the use of "Profiler Plus," a nonaplex of STRs combined with amelogenin, a locus utilized for sex determination. This paper reports the results from a case where a mutation in the annealing region of the amelogenin primers appears to have resulted in the failure to amplify the amelogenin Y-homolog from a phenotypically normal male. The result was confirmed using two different primer sets that amplify different regions of the amelogenin gene. This situation suggests that the genetic determination of sex based on the amelogenin sequences from specimens of unknown origin, such as crime scene samples, should not be considered infallible.