Objective: Trisomy 21 is a genetic disorder that shows premature aging symptoms. As an aging marker, telomere length is therefore of importance in trisomy families. Methods: We included 63 maternally originated trisomy 21 and 77 control families with infants in the first data set; 48 trisomy 21 and 60 control children in the second set; and 14 paternally originated trisomy 21 families in the third data set. We used Southern blot to measure the telomere length. Results: (1) Offsprings' telomere length increased with parents' age (p < .0001). (2) Trisomy 21 infants had longer telomere than the controls (p < .0001). (3) Post-birth, the telomere attrition rate was higher in cases than in controls (58 bps/year vs. 38 bps/year). Conclusion: (1) Our data supports the older parents-longer gamete telomere hypothesis. (2) Trisomy 21 patients are born with longer telomeres, (3) with advancing trisomy 21 age, the telomere shortens more quickly than euploids.
Keywords: Down syndrome; India; Trisomy 21; telomere length.