Analysis of somatic cell mutations at the Glycophorina locus in human erythrocytes

Abstract

Introduction: Dose evaluation of exposed humans to radiation becomes necessary after exposure. Such a dose evaluation can be done by biological dosimetric methods of which increased somatic cell mutant frequencies in exposed individuals can be a reliable index [1]. Biological dosimetry has an important role to play in assessing the cumulative radiation exposure of persons working with radiation and also in estimating the true dose received during accidents involving external and internal exposure. Biodosimetric methods include cytogenetic, immunological and mutational assays [2]. The need for biodosimetry is essential for caliberating the actual dose received to a biological system where other conventional forms of dosimetry are unavailable. Even in the presence of other dosimetric tools such as Thermo Luminescent Devices (TLDs) etc, biological dosimetry gives actual doses apart from an indication of the extent of damage caused by such damages. This becomes all the more important with the current situations such as space programmes and dirty bombs. There are currently many advancing methods for measuring somatic mutations and new opportunities for biological dosimetry of high-risk groups. An evaluation of such mutations becomes all the more important, as such mutations can be possible predictors of cancer risk [3]. Somatic mutations can now be measured in several human genes. The genes currently used include the hemoglobin (Hb) genes on chromosome 11 and 16, the glycophorin A (GPA) gene on chromosome 4, the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene on the Xchromosome, the HLA genes on the chromosome 6 and the T-cell receptor (TCR) genes on chromosomes 7 and 14. Of the various assays for somatic mutations, only GPA and HPRT have been studied sufficiently to have reliable databases. With increasing interest in the GPA mutation assay for biodosimetry and assessment of health risks, the techniques used to detect the variant cells have been undergoing constant changes and evolution from 1986