Heterochromatin Polymorphism as A Significant Factor in Recurrent Abortions

Background: Heterochromatin polymorphism is considered a variant of a normal karyotype but is more frequent in recurrent abortions. The aim of the present study was to investigate the contribution of chromosomal abnormalities and the frequency of a particular type of aberration in couples of north Iranian population origin with recurrent abortions compared with patients without abortions. Methods: In this study 400 couples with recurrent abortions and 400 couples without recurrent abortions were before 6rd months of pregnancy who were introduced to the Medical Genetic Laboratory of Dr. Keshavarz in Rasht. Standard in vitro lymphocyte culture was used for chromosomal analysis. The chromosomes were banded using the Giemsa-Trypsin-Giemsa (GTG) banding technique, and twenty metaphases with a resolution of 450-550 bands were evaluated under a light microscope. Results: The chromosomal analysis revealed in abortion group a total of 22(5.5%) heterochromatin polymorphism, among these,13(3.25%) male patients while 9(2.25%) female patient was affected. While in normal group heterochromatin polymorphism were observed in 7 (1.75%) of the whole group. The result of this study show that heterochromatin polymorphism in patients with recurrent abortions is significantly higher than that of normal population (P< 0.01). Conclusion: Although heterochromatin polymorphisms are considered by most clinicians as polymorphisms without any phenotypic effect, there are a number of studies showing acorrelation with reproductive failure. It seems that heterochromatin polymorphisms is common in patients with spontaneous abortion and intrauterine fetal death can be seen, the chromosomal abnormalities can play as a key rule for recurrent abortions.

Keywords:

Cytogenetics , Heterochromatin Polymorphism , Recurrent Abortions