Detection and relevance of germline genetic polymorphisms in glutathione S-transferases (GSTs) in breast cancer patients from northern Indian population.

INTRODUCTION: Glutathione S-transferases (GSTs) are polymorphic superfamily of detoxification enzymes that detoxify therapeutic drugs and various carcinogens. We undertook a case-control study in northern Indian population based sample consisting of 413 patients and 410 controls to evaluate association of null genotype in GSTM1 and GSTT1 along with polymorphism in GSTP1 (A-->G) with breast cancer risk. METHODS: Genotyping analyses were performed by PCR-based methods, and odds ratios (ORs) were calculated by unconditional logistic regression analysis adjusting for various confounding factors. RESULTS: In this case-control study, we observed a positive correlation between family history of breast cancer and risk of breast cancer (OR = 2.06; 95% CI = 1.47-2.92). We found a significantly increased breast cancer risk associated with GSTM1 null genotype (OR = 2.28; 95% CI = 1.65-2.97) and homozygote mutants in GSTP1 (OR = 2.59; 95% CI = 1.67-4.39). However, we found no association between GSTT1 null genotype with overall breast cancer risk (OR = 1.04; 95% CI = 0.76-1.59). The three-way combination of GSTP1 105AA/AG and null genotypes for both GSTM1 and GSTT1 resulted in fourfold increase in breast cancer risk (OR = 4.02; 95% CI = 1.99-8.51). CONCLUSION: The findings of this study are in line with previously published reports that show an overall association with GSTM1 and GSTP1 polymorphisms with breast cancer risk. Our results suggest that the variants in low penetrance genes such as GSTM1, GSTT1 and GSTP1 are associated with an increased breast cancer risk thereby suggesting their contribution in the etiology of breast cancer.

Does mutation of hepatitis A virus exist in North India?

BACKGROUND: Human hepatitis A, a widespread infectious disease that is hyperendemic in vast areas of the world, results in the infection of the liver. Different human HAV strains of diverse geographic origin are remarkably closely related. HAV exploits all known mechanisms of genetic variation to ensure survival, including mutation and genetic recombination. OBJECTIVES: The aim of the study was to undertake an in-depth analysis of the mutation in three groups: (i) mild acute hepatitis (m-AH), (ii) severe acute hepatitis (s-AH), and (iii) fulminant hepatitis (FHF) A patients, who were tested positive for HAV RNA. MATERIALS AND METHODS: A total of 500 patients of acute viral hepatitis (AVH) were screened for HAV-IgM positivity from January 2003 to December 2004. HAV RNA positivity was subject to reverse transcription of RNA followed by polymerase chain reaction (RT-PCR) for the detection of HAV RNA. The HAV RNA positive cases were subject to single-stranded conformational polymorphism (SSCP). RESULTS: Out of 500 acute cases of hepatitis, 80 (16%) were positive for HAV-IgM. HAV RNA was detected in 34 (42.5%) cases by RT-PCR. Twenty-four (70.5%) were m-AH, seven (20.5%) were s-AH, and three (8.8%) were FHF. All the positive samples were subject to SSCP. No mobility shift was observed with respect to any screened samples by PCR-SSCP. Four (m-AHI-54, m-AHI-80, s-AHI-341 and FHFI-195 suspected cases were directly sequenced to prove that there was no point mutation. CONCLUSION: SSCP demonstrates no mobility shift in the VP1/P2A region of the HAV genome. No point mutation was observed in the four suspected cases by sequencing. However a large study from different geographical locations is needed to achieve a logical conclusion about the existence of HAV mutation in the Indian population.