Shown is an image of a thin section showing the ultrastructure of the nucleus and nuclaer envelope in fibroblast from a Hutchinson-Gilford Progeria syndrome patient which carries a mutation in the gene for lamin A, a major component of the nuclear lamina (left and center). The passage 26 cell shows marked abnormalities in the nuclear envelope. Also shown is envelope from a normal fibreblast. Other images in this group show the distribution of other nuclear envelope components in HGPS fibroblasts. See Fig 3 in R.G. Goldman et al. 2004 Proc Natl Acad Sci 101:8963-8968.