ZMPSTE24 and Hutchinson-Gilford progeria syndrome: Despite their HGPS classification in the Coriell repository, four patient samples (HGPS 13, 17, 19, 20) lacked the classic HGPS mutation in the LMNA gene and no progerin mRNA was detectable (Fig. 1 A–C; Fig.S1A–B; Table 1).