ABSTRACT
Polymorphisms of the size of heterochromatin regions and abnormalities of chromosomes have been well documented in human genome; they consist of DNA sequences that are not transcribed. The prime aim of the present study was to evaluate the heterochromatin polymorphism and numerical and structural abnormalities associated with chromosomes in drug addicts. No data exists in Iran regarding the cytogenetic characteristics of drug addiction lymphocytes. Therefore, cytogenetic investigations were performed in 93 drug addiction lymphocytes and 93 normal controls. This randomized collected study was conducted on 93 consecutive drug addiction individuals and 93 healthy individuals in Loghman and private hospitals, Tehran, Iran between the years 2007-2009. By applying Barium Hydroxide saline Giemsa [BSC] method, the variant heterochromatin polymorphism of chromosomes 1, 9 and 16 on lymphocyte cultures were evaluated. Cytogenetic analysis was performed in drug addicts' lymphocytes cultures.Constitutive heterochromatin polymorphism of chromosomes 1 in drug addicts revealed statistical significant when compared with chromosome of healthy controls [P=0.004]. The differences were significant for chromosome 9 [P=0.029], it was 94.1% in drug addiction and 5.9% in the control group [P=0.196]. The differences were also significant for chromosome 16: it was 91.9% in addicts and 8.1% in the control group [P=0.052]. Also the frequency of partial and complete inversion did not show any significant differences between the drugs addicts and the control group. The occurrence of chromosomal defects including, chromatid break [12 addicts], chromatid gap [8 addicts], dicentric [2 addicts], was higher in our observation. Our constitutive heterochromatin polymorphism blocks and chromosomal abnormalities in drugs addicts' chromosome may provide an opportunity to serve as a marker for the detection and characterization of the damages chromosomes in drug addicts