Karyotyping and counseling in bad obstetric history and infertility|
Sayee Rajangam, Preetha Tilak, Aruna N, Rema Devi
Background: Division of Human Genetics (DHG) is a referral center for karyotyping and counseling to the couples as well as to the individuals referred with bad obstetric history and infertility.
Materials and Methods: From 1972 to 2003, overall 1666 couples and 131 female partners with bad obstetric history (BOH) such as; spontaneous abortions, live births with congenital malformations and still born and 73 infertile male partners have been referred for chromosomal analysis.
Results: The chromosomal abnormality was found in 4.4% (83) of the sample studied. Chromosomal abnormality was seen in 56 couples (3.4%), 15 female (11.5%) and 12 male (16.4%) partners. The numerical chromosomal abnormality were seen in 34 (41%) and the structural abnormalities in 49 (59%) cases. The numerical chromosomal abnormalities were associated with sex chromosomes as follows (the number of cases are shown in parenthesis): 47, XXY (9); 46, XY/ 47, XXY (2); 46, XY/ 48, XXXY (1); 46, XY/ 47, XYY (2) and X mosaicism; 45, X/ 46, XX (14); 46, XX/ 47, XXX (6). The structural anomalies were 40 translocations and 9 duplication/ deletion/ marker/ iso chromosome for the X chromosome; Male: 46,XY/ 47,XY+ mar (1); Female: 45,X/ 47,XX+mar (1); 46,XX/ 47,XX+mar (1); 47,XX+frag (1); 46,X,Xq- (2); 46,X,Xp- (1); 46,X,Xp+ (1); 45,X/46,X,i(Xq)(1). The frequently involved chromosomes in the translocations were 4, 11, 15 and X. There were three X; autosomal translocations and a unique combination of translocation 1; 15 in the parents of a female carrier and 13; 14 in a non- consanguineous couple. On the whole, 57.5% of the females (23/ 40) were translocation carriers. Non-significant chromosome polymorphisms were observed in 79 cases (4.2%).
Conclusion: The current study has demonstrated the presence of the chromosomal abnormality and its influence in reproductive failure. On an average, in this study one in 56 couple and one in 12 males with infertility or one in 15 females with BOH has had a chromosomal abnormality as the genetic cause. The identification of chromosomal abnormality as the etiology has facilitated the counseling and appropriate management.
Chromosomal abnormality, Bad obstetric history, Infertility, Genetic counseling