FISH-based analysis of radiation-induced chromosomal aberrations using different nomenclature systems

Abstract

Purpose: Comparison of three nomenclature systems for the description of chromosomal aberrations involving painted chromosomes (PAINT, S&S and a conventional method) by parallel application to one data set. Materials and methods: Radiation-induced (3 Gy 220 kV X-rays) chromosome aberrations in human lymphocytes were analysed by FISH-painting of seven single chromosomes (1, 3, 6, 7, 8, 10 and 14) simultaneously with a pancentromeric probe. Results: Each system is based on different prerequisites and uses different criteria for the classification and quantification of structural chromosome aberrations. Due to the frequent occurrence of complex exchanges (resulting from 3 breaks on 2 chromosomes), standard cytogenetic scoring criteria used for solid-stained preparations are inadequate for a precise and reproducible classification of aberrant painting patterns. S&S is particularly suitable if a mechanistic interpretation of aberration origins is required. The descriptive terminology of PAINT enables a rapid, reproducible description, even of most extensively rearranged chromosomes by classifying each abnormal painting pattern individually. Conclusion: A modification of PAINT criteria, allowing also for mechanistic aspects, would be most advantageous for practical application.