Trisomy 21 and accelerated aging: DNA-repair parameters in peripheral lymphocytes of Down's syndrome patients

Down's syndrome (DS) cases from 1-40 years of age and showing no other anomalies or deficiencies were categorized into three age groups: group 1, < or = 12 years; group 2, 13-25 years; and group 3, > or = 26 years. The DNA-repair markers like unscheduled DNA synthesis (UDS), activities of DNA polymerases, (Total, beta and epsilon) and two endodeoxyribonucleases, (UV- and AP-DNases) were assessed in the peripheral lymphocytes of these subjects (under different conditions) along with age and sex matched normal healthy human subjects. The DS group showed lower DNA-repair efficiency and also an accelerated decline in DNA-repair capacity with age. These results indicate that deteriorated DNA-repair potential could be one of the probable reasons for premature aging seen in this chromosomal disorder.