LMNA and Hutchinson-Gilford progeria syndrome: However, these age-related dysfunctions are only partially recapitulated in iPSC-derived neurons, which have no discernable heterochromatin changes upon overexpression of truncated lamin A. Furthermore, the HGPS model lacks a mechanistic explanation, as less than 1% of fibroblasts isolated from elderly donors express progerin (McClintock et al. 2007).