ANALYSIS OF SOMATIC CELL MUTATIONS AT THE GLYCOPHORIN GLYCOPHORINA LOCUS IN HUMAN ERYTHROCYTES

Abstract

Introduction: Dose evaluation of exposed humans to radiation becomes necessary newlineafter exposure. Such a dose evaluation can be done by biological dosimetric methods newlineof which increased somatic cell mutant frequencies in exposed individuals can be a newlinereliable index [1]. Biological dosimetry has an important role to play in assessing the newlinecumulative radiation exposure of persons working with radiation and also in estimating the true dose received during accidents involving external and internal newlineexposure. Biodosimetric methods include cytogenetic, immunological and newlinemutational assays [2]. newlineThe need for biodosimetry is essential for caliberating the actual dose received to a newlinebiological system where other conventional forms of dosimetry are unavailable. newlineEven in the presence of other dosimetric tools such as Thermo Luminescent Devices newline(TLDs) etc, biological dosimetry gives actual doses apart from an indication of the newlineextent of damage caused by such damages. This becomes all the more important newlinewith the current situations such as space programmes and dirty bombs. newlineThere are currently many advancing methods for measuring somatic mutations and newlinenew opportunities for biological dosimetry of high-risk groups. An evaluation of newlinesuch mutations becomes all the more important, as such mutations can be possible newlinepredictors of cancer risk [3]. Somatic mutations can now be measured in several newlinehuman genes. The genes currently used include the hemoglobin (Hb) genes on newlinechromosome 11 and 16, the glycophorin A (GPA) gene on chromosome 4, the newlinehypoxanthine-guanine phosphoribosyltransferase (HPRT) gene on the Xchromosome, newlinethe HLA genes on the chromosome 6 and the T-cell receptor (TCR) newlinegenes on chromosomes 7 and 14. Of the various assays for somatic mutations, only newlineGPA and HPRT have been studied sufficiently to have reliable databases.