Sequencing of the short cDNA product derived from RNA preparation of a 93 year-old donor was found to be identical to the progerin cDNA sequence (Fig. 1B), demonstrating that the progerin transcript, previously identified as an aberrant lamin A product in HGPS, might constitute a true physiological lamin A isoform. This evidence concerns the gene LMNA and Hutchinson-Gilford progeria syndrome.