Frequencies of GSTM1and GSTT1 polymorphisms in Iraqi population

Abstract EN

The glutathione S-transferase (GST) family of enzymes has a vital role in phase II of biotransformation of environmental carcinogens, pollutants, drugs and other xenobiotics.

GSTs are polymorphic, with the type and frequency of polymorphism being ethnically dependent.

Polymorphisms in GSTs genes have been shown to be associated with susceptibility to disease and disease outcome.

The frequencies of GSTM1 and GSTT1 polymorphisms are determined in 160 Iraqi volunteers who had been residents of different areas of Baghdad and Basrah.

Blood was collected and DNA extracted by proteinase K/SDS digestion.

GSTM1 and GSTT1 polymorphisms were analyzed by a PCR-Multiplex procedure.The multiplex PCR protocol was used to simultaneously analyze the presence or absence of gstm1and gstt1 genes.

The Albumin gene was used as an internal control(350 bp) whereas the presence of the GSTM1 and GSTT1 genes was identified by 215 and 480 bp fragments, respectively.

Although these assays do not distinguish between heterozygote and homozygote positive genotypes, they conclusively identify the null genotypes (the genes are completely deleted).

The genetic analysis showed that the deletion percentage in the samples was 30% (GSTM1 13.1 % and null genotype 10% and 6.9 % for GSTT1) as compared to 70% that was normal.

The detected deletions in our population(30 %)appear to be lower than or similar to the frequencies of these polymorphisms in other Western countries.

But they are lower than those found in Asia.