Effect of drugs on the sex chromatin

ABSTRACT

This work was conducted to study the effect of different including corticosteroids, immunosuppression, antibiotics, anti T.B. and hormones as thyroxine and insulin on the size and prevalence of the sex chromatin. Patients were chosen from the pediatric department, genetic unit, Cairo University and from the department of Chemotherapy in Cancer Institute. Their ages ranged from 2-50 years. The duration of treatment was variable according to the type of medicines used. 50 normal females of the same age group, not receiving any treatment in the previous 6 months were taken as controls. Buccal smears were taken and examined to study the prevalence of sex chromatin and its size. All the drugs used were observed to cause a marked reduction in the prevalence of the sex chromatin which proved to be statistically significant. This may be due to inhibition of DNA synthesis and DNA replication by some medicines while it is due to partial activation of the super-coiled chromatin resulting into its despiralisation and elongation as well as cell multiplication in other types of medicines. Only patients receiving antibioties showed a statistically significant reduction in the size of the Barr body which was interpretation by their inhibitory effect on DNA duplication