GENDER VERIFICATION IN SPORTS BY PCR AMPLIFICATION OF SRY AND DYZ1 Y-CHROMOSOME SPECIFIC SEQUENCES - PRESENCE OF DYZ1 REPEAT IN FEMALE ATHLETES

Objective-To perform genetic sex typing during the Barcelona Olympic G ames using polymerase chain reaction (PCR) amplification of Y chromoso me specific sequences. Methods-The assay consisted of the amplificatio n of a specific sequence corresponding to the repeat DYZ1 element from buccal smears samples of 2406 female competitors. Positive samples we re reanalysed for the presence of another Y chromosome specific gene, SRY. Results-The expression of these two elements did not always corre late; six samples were found where the presence of DYZ1 but not SRY wa s detected. This presence of DYZ1 sequence in female athletes is highe r than in unselected females, where no DYZ1 amplification was observed in any of the 1629 samples analysed.Conclusions-Amplification of DYZ1 repeat should not be used as the only index for determining genetic s ex, at least in sporting events.