Background: The etiology of aplastic anemia (AA) may be multifactorial and toxic environmental factors have been postulated to contribute to the etiology of AA. It is possible that patients with reduced ability to metabolize environmental carcinogens or toxins are at risk for developing AA. The (GSTM1) and (GSTT1) members of the glutathione S-transferase multigene family are polymorphic in human beings and have been implicated in detoxifying mutagenic electrophilic compounds. An increased frequency of OST null genotypes has been associated with several malignancies. We studied whether the homogygous null genotypes of GSTM1 and GSTT1 would alter the risk for AA and the relationship of the GST genotype to the chromosomal abnormalities in AA patients to clarify the multistep pathogenesis of AA based on this possible genetic predisposition. Methods: We analyzed bone marrow samples from 57 AA patients and peripheral blood samples from 75 healty controls of similar age and sex. Multiplex PCR was performed on extracted DNA to co-amplify the GSTM1 and GSTT1 alleles, and CYP1A1 as an internal control. Results: The GSTM1 null genotype was found in 47/57 (82.5%) AA patients and 45/75 (60.0%) controls. The GSTT1 null genotype was found in 41/57 (71.9%) and 34/75 (45.3%) controls. Most of the AA patients showed GSTM1 null genotype [odds ratio (OR) : 3.1, 95% confidence interval (CI), 1.4-7.1, P=0.01). The incidence of GSTT1 null genotype was also significantly higher [OR : 3.1, 95% CI, 1.5-6.4, P=0.004] for AA patients. Of the 57 AA patients, 9 patients(15.8%) had chromosomal abnormalities at the time of diagnosis. And, all the AA patients with chromosomal abnormalities showed GSTT1 null genotype(P=0.05). Conclusions: The frequencies of GSTM1 and GSTT1 null genotypes are significantly higher in Korean AA patients. Especially, genetic instability or chromosomal damage due to abnormal detoxification of environmental or endogenous toxins might be important pathophysiologic mechanism of AA in the patients with GSTT1 null genotype.
|Issue number||11 PART I|
|Publication status||Published - 2000 Dec 1|
All Science Journal Classification (ASJC) codes
- Cell Biology