Comparative Study of Prenatal Diagnosis by Karyotype and Microarray in Cases of Balanced Translocation Carriers of Parents and Finding in Fetuses

Background: The prenatal diagnosis was carried out to analyze the results providing scientific clinical guidance for prenatal screening. Furthermore, analysis of women in progressive maternal stage helped in finding out the chromosomal abnormalities in the form of translocations. Hence, the objective of the study was to analyze the correlation between clinical indication and chromosomal patterns for translocations in high-risk pregnancies. Materials and Methods: A total of 200 women between 21 and 41 years of age who underwent prenatal diagnosis were selected for the study. At the gestation age of 9–20 weeks, they underwent genetic counseling as well. The samples (chorionic villus sampling and amniotic fluid) were collected after consideration of high-risk factor with informed consent. The karyotyping and fluorescent in situ hybridization (FISH) were performed to find out the any chromosomal translocation and to confirm the type of translocation (balanced and unbalanced) microarray technique was used. Results: Results indicated that 5 out of 200 cases were reported for balanced translocation, in which one case was reported for balanced translocation between chromosomes 13 and 22 in karyotype while the FISH and microarray results were normal. In the second case, a translocation between chromosomes 13 and 20 was found, the FISH was normal and the microarray showed arr20q11.2(29,835,035-30,117,285) x3 with a variant of uncertain significance. The third case was reported for translocation between chromosomes 13 and 15, the fourth case was reported for balanced translocation between chromosomes 3 and 9, whereas the fifth case was reported for balanced translocation between chromosomes 2 and 20. Conclusions: To be concluded, 2.5% of women were recorded for balanced translocation 3 out of 5 translocation cases indicated the balanced translocation to be coming from the parents either mother or father. Clinical indications after karyotype results showed translocations in all cases which were transferred from parents, but in two cases, the balanced translocation was observed for the first time, and it is called de novo . In this case, the parent did not contribute to the balanced translocation, and it may be due to abnormal gametogenesis.