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Int J Mol Epidemiol Genet 2012;3(2):153-159

Original Article
Association of glutathione S-transferase T1 and M1 genotypes with chronic
liver diseases among Filipinos

Michael O Baclig, May R Alvarez, Xerxes Morgan R Lozada, Cynthia A Mapua, Jingky P Lozano-Kühne, Mark Pierre S Dimamay,
Filipinas F Natividad, Juliet Gopez-Cervantes, Ronald R Matias

Research and Biotechnology Division; Liver Disease and Transplant Center, St. Luke’s Medical Center

Received April 13, 2012; accepted May 9, 2012; Epub May 15, 2012; Published May 30, 2012

Abstract: The glutathione S-transferase (GST) supergene family is made up of four gene families responsible for the
biotransformation of drugs and other xenobiotics. Genetic variations in this supergene family influence individual detoxification
levels and may contribute to the development of cancer. A hospital-based case-control study was conducted to evaluate the
association between GST polymorphism among Filipino patients positive for hepatitis B virus (HBV DNA) and clinically
diagnosed as either with chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma as well as normal individuals
negative for HBV infection. Multiplex PCR was used to detect the presence or absence of the GSTT1 and GSTM1
polymorphisms in peripheral blood. DNA sequencing of the S gene region of the virus was used to determine the predominant
genotype found among HBV-infected patients. Our results showed that the odds of having a chronic liver disease is only 0.95
(95% CI 0.58-1.57) among those with GSTT1- null genotype compared to those with GSTT1+ genotype. On the other hand, the
odds of chronic liver disease is 17.85 times (95% CI 7.34-43.45) for those with GSTM1- null genotype compared to those with
GSTM1+ genotype. Using the GSTT1+/GSTM1+ genotype as the reference, both GSTT1+/GSTM1- (OR 16.61; 95% CI 6.69-
41.22) and GSTT1-/GSTM1- (OR 11.91; 95% CI 4.48-31.66) genotypes seem to be risk factors for chronic liver disease. From
our observations, we conclude that polymorphism in GSTM1- null genotype (OR 17.85; 95% CI 7.34-43.45) seem to be
associated with an increased risk of chronic liver disease among Filipinos. (IJMEG1204004).

Keywords: GSTT1, GSTM1, chronic liver disease, hepatitis B virus, polymorphism, Filipino

Address all correspondence to:
Dr. Michael O Baclig
Research and Biotechnology Division
St. Luke’s Medical Center
279 Eulogio Rodriguez Sr. Blvd
Quezon City, 1102 Philippines.
Tel: (632) 727-55-40; Fax: (632) 726-04-67
E-mail: mobaclig@stluke.com.ph