The heritable translocation assay: its relationship to assessment of genetic risk for future generations

The Heritable Translocation Assay (HTA) is an in vivo mammalian mutation test which measures specific clastogenic damage. It can be subjected to rigorous statistical scrutiny and detects a type of heritable genetic damage that is known to contribute to the human disease burden. Because of these factors the HTA is one of the major tests of the battery used in regulatory evaluation of potential environmental mutagens. Although tests for detecting inherited translocations have been developed and improved over the past 40 years, further emphasis on several statistical considerations affecting the precision and reliability of HTA animal model data applied to regulatory hazard evaluation and risk assessment seems warranted. In this paper we have presented a brief history and the basic methodology for the HTA. Statistical concepts related to the design and implementation of HTA studies, such as the incorporation of false classification error probabilities in determination of required sample size and use of the single sample binomial versus Fisher's exact test for analysis of data, hory and the basic methodology for the HTA. Statistical concepts related to the design and implementation of HTA studies, such as the incorporation of false classification error probabilities in determination of required sample size and use of the single sample binomial versus Fisher's exact test for analysis of data, hory and the basic methodology for the HTA. Statistical concepts related to the design and implementation of HTA studies, such as the incorporation of false classification error probabilities in determination of required sample size and use of the single sample binomial versus Fisher's exact test for analysis of data, have been examined in detail. We have also suggested a simplified method of extrapolating HTA animal data to man similar to that used with carcinogenesis data and propose other developmental needs and perspectives for application of this assay to regulatory assessment of environmental mutagens.