Human lymphocyte telomerase is genetically regulated.

Research on both cancer and aging has focused attention on the regulation of telomerase, the enzyme that synthesizes the ends of chromosomal DNA. To analyze the relative importance of genetic vs. environmental factors in determining telomerase inducibility, we have compared telomerase activity in phytohemagglutinin-stimulated peripheral blood lymphocytes from monozygotic and dizygotic twin pairs. The heritability calculated was 0.814, indicating that lymphocyte inducible telomerase activity is determined principally by genetic rather than by environmental factors.