Impaired proliferation response after PDGF induction in fibroblasts from Hutchinson-Guilford Progeria syndrome

Fibroblasts from a Hutchinson-Guilford Progeria Syndrome (HGPS) patient were compared to normal human fibroblasts to determine if differences existed in growth factor mediated cell proliferation. Cultures of progeric fibroblasts were exposed individually to platelet-derived growth factor (PDGF), epidermal growth factor (EGF), platelet poor plasma (PPP) and fetal bovine serum (FBS). Autoradiographic studies using 3H thymidine showed that progeric fibroblasts had similar labeling indices relative to controls after exposure to FBS and EGF. In contrast, progeric cells made competent with PDGF and later treated with 5% PPP had a significantly lower labeling index. This and preliminary observations on fos RNA accumulation suggests the possible existence of a genetic defect in HGPS fibroblasts.     

Revised transthyretin Ile 122 allele frequency in African-Americans

The transthyretin (TTR) Ile 122 variant is associated with cardiac amyloidosis in individuals of African descent. To determine the prevalence of the allele encoding TTR Ile 122 in African-Americans, we have used PCR and restriction analysis to test DNA from African-Americans from various geographic areas, and found an allele frequency of 66/3376 (0.020), which is higher than the value we previously reported in a much smaller pilot study. Our data indicate that this TTR variant is present at equal frequency in African-Americans throughout the U.S., and suggest that this mutation may be a common, often unrecognized cause of cardiac disease in African-Americans. Received: 23 January 1996