MT1A (A>G), MT1A (C>G), MT1M (A>C) and MT4 (G>A) single nucleotide polymorphism allele frequencies in Iranian populations

Abstract

It has been widely reported that metallothioneins (MTs) play pivotal roles in the metabolism of the relatively nontoxic essential metals, as well as of toxic heavy metals. MT gene polymorphisms in an individual may increase or decrease the expression efficiency of the gene. The present study was aimed to investigate the frequency of genetic variation of four MTs in the Iranian population. Whole blood samples were collected from 300 Iranian healthy individuals. Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) and automated Sanger sequencing were used for DNA genotype determination. The frequencies of major homozygous, heterozygous and minor homozygous genotypes in MT1 (A>G) were, respectively, 76.0%, 24.0% and 0.0%; in MT1A (C>G), 88.0%, 12.0% and 0.0%; in MT1M (A>C), 86.0%, 14.0% and 0.0%; in MT4 (G>A), 80.0%, 18.7% and 1.3%. The present study showed for the first time that the polymorphism frequency distribution of these four MTs significantly differed between the studied Iranian population and other populations around the world, except for the MT4 polymorphism in the Iranian population and populations from the USA and New Zealand, which were similar. In conclusion, it could be suggested that regional and ethnic differences are the main reasons for this varied prevalence.