TRIPLOID KARYOTYPES IN PRENATAL DIAGNOSIS AT UNIVERSITY CLINICAL CENTER OF REPUBLIC OF SRPSKA

Abstract

Triploidy is chromosomal abnormality characterized by the presence of three sets of chromosomes instead of the normal two sets, so the triploid fetus has 69 chromosomes. Within the Department for medical genetics at University Clinical Center of Republic of Srpska, from 2009 to 2016, 5853 prenatal karyotipizations were performed from amniotic fluid. Two cases (0,03%) of tryploid karyotipe were detected during this period. In this report we will present the findings of triploid karyotype 69, XXX in prenatal diagnosis. Origin of those triploid karyotipes was determined using molecular methods at Institute of Forensic Medicine of Republic of Srpska, Banja Luka. One of the detected triploid fetuses originated from twin pregnancy, where the pregnancy was spontaneously aborted two weeks after amniocentesis. Using molecular methods, it was determined that one set of chromosomes originated from the mother, and two sets from the father- diandric origin. The other triploid fetus originated from one fetus pregnancy, where the pregnancy was spontaneously aborted two weeks after amniocentesis. The first trimester combined test indicated triploid kariotype with digyny origin. Triploid karyotype was confirmed by prenatal karyotipisation, while molecular analysis confirmed digyny origin of this case of triploidy – two sets of chromosomes originated from mother and one set from father. Since cytogenetic analyses are performed from amniotic cells at 16-18 weeks, in order to reduce waiting period, parents should be informed about karyotypisation and DNA profiling from chorionic villi sample at 11-12 weeks as a faster option to get final results .