Abstract
Somatic cell mutant frequencies at the hprt locus of the X-chromosome were measured with the T-lymphocyte cloning technique in healthy human populations. A statistical analysis was performed of assays from 232 individuals (77 males and 155 females) ranging in age from 19 to 80 years. Data from 4 donor groups were compiled: (a) 132 participants in a study of identical and fraternal twins; (b) 17 health care workers studied as part of an assessment of the risks of handling chemotherapeutic drugs; (c) 62 women with benign breast masses; and (d) 21 normal laboratory and office personnel. The relationship between age and mutant frequency (MF) was expressed by the equation: In MF = 1.46 + 0.018 age (P<0.001). Thus, MF increased by about 2% per year. Increases in cloning efficiency (CE) reduced the MF, as shown in the equation: In MF = 2.91-1.32 CE (P<0.001). CE was significantly related to age (CE = 0.47-0.002 age, P = 0.038), and the interdependent relationship between MF, age and CE expressed by the equation: In MF = 1.99-1.13 CE + 0.016 age was significant at the P<0.001 level. There was no statistically significant effect of donor gender or smoking history on MF in our population, but CE was significantly lower in males (P< 0.001). These findings confirm the importance of age and CE as factors which influence the thioguanine-resistant MF in circulating T-lymphocytes from normal adults.
Original language | English (US) |
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Pages (from-to) | 267-279 |
Number of pages | 13 |
Journal | Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis |
Volume | 285 |
Issue number | 2 |
DOIs | |
State | Published - Feb 1993 |
Keywords
- 6-Thioguanine-resistant
- HPRT
- Human population monitoring
- T-lymphocytes