Telomere length analysis of DC PB. Longitudinal data were obtained over a period of 20 months for 2 of the DC subjects, at 1, 15, and 20 months, respectively from the second generation (UPN 5, filled circles) and third generation (UPN 9, squares) of the DC family. These analyses of mean telomere lengths of PB lymphocytes and granulocytes are shown relative to normal telomere distribution curves derived from best-fit analysis for 400 healthy individuals (Baerlocher and P.M.L., unpublished data, August 2001).