Chromosomal polymorphism in the cases of habitual spontaneous abortus and bad obstetric anamneses

ABSTRACT Chromosomal Polymorphism in the Cases of Habitual Spontaneous Abortus and Bad Obstetric Anamneses In this study, C- and NOR-banding techniques were used to determine the occurence and importance of chromosomal polymorphism in the cases of habitual spontaneous abortus (HSA) and bad obstetric anamneses (BOA). Subject and control groups were composed of 30 couples, each (a total of 180 cases). Twenty metaphase plaques were evaluated for each case. In the C-banding technique; centromere region of the chromosomes, and 1/2-1/3 distal region of the long arm of Y chromosome were stained dark. Heterochromatin regions stained in the chromosomes 1,9,16 and Y, especially showed polymorphism. In this study, sizes of heterochromatin regions in the chromosomes were evaluated on the basis of 5 -point system, and the difference between the subject and control groups was found to be significant when analysed by Chi-Square test. In the NOR-banding technique, short arms of acrocentric chromosomes (13,14,15,21,22) were stained dark. In this technique, the banding patterns showed polimorphism in terms of number and size. The average number of NOR observed in the humans is about 4-10. Except chromosome 21 in the females and chromosome 22 in the males, the difference was found to be nonsignificant in the HSA group. Overall evaluation of our results led to the conclusion that NOR-and especially C-banding should be performed in these subject groups, besides the G- banding technique. Keywords: Chromosome, Polymorphism, C-banding, NOR-banding. IX