RÉSUMÉ
Detection of a Y-specific sequence in either amniotic cells or the maternal circulation has clinical importance for prenatal sex diagnosis, especially in mothers with severe X-linked disorders. Deoxyribonucleic acid sequences of human ZFY (zinc-finger-Y) gene, a Y-chromosome-specific gene and candidate for the testis-determining factor, were amplified by in vitro nested PCR technique, in amniotic cells or peripheral blood of Thai pregnant subjects carrying male fetuses. This technique permits detection of ZFY gene DNA sequences in as few as a single male cell among 100,000 female cells. The subjects in this study were a group of Thai pregnant women who had been given prenatal fetal sex diagnosis by the cytogenetic method. The results herein demonstrated the usefulness of PCR detection of Y-specific sequences in amniotic cells. The ZFY gene detection method for prenatal sex prediction by nested PCR has been developed experimentally. However, further investigation is necessary to increase reliability of clinical application. With properly designed guidelines, the established nested-PCR technique may be an alternative for the determination of the fetal sex for those pregnancies at risk of X-linked genetic disorders.