人類遺伝学と発生学

Background: There are very few studies on reproductive outcomes in couples with balanced chromosomal translocations. Findings of such studies can shed light on the possible future outcomes and help in genetic counselling. Objectives: The overall objectives of this study were to report the various chromosomal balanced rearrangements in couples with history of bad reproductive history, to analyse the reproductive outcomes prior to the evaluation and to compare the chromosomal findings with the similar available data from literature. Methods: Reproductive history of couples identified with balanced chromosomal translocations at Genetic Health and Research Centre, Nashik was studied retrospectively, and the various pregnancy outcomes were tabulated and compared with the available literature data. Results: Out of 1580 couples investigated for chromosomal abnormalities for the various indications like recurrent miscarriages, infertility, intrauterine deaths, stillbirths, children with birth defects and neonatal deaths, 101 (6.39%) were found to be carriers of balanced chromosomal rearrangements. A total of 334 pregnancies (average 3.2) were documented in all these carriers. The mean maternal age at the time of evaluation was 29.4 years. Various reproductive outcomes documented were pregnancy losses in 290 couples (2.87 per couple), abnormal births in 25 couples, infertility in 9 couples and normal birth in 19 couples. Conclusion: Karyotyping of couples with bad reproductive outcomes is highly useful for further genetic counselling, appropriate management and close monitoring in subsequent pregnancies. Carriers of balanced chromosomal translocations have better chances of having a normal live birth, however the risk of having the birth of offspring with chromosomal abnormality need to be taken into consideration and prenatal diagnosis offered in all future viable pregnancies.