Werner's syndrome: a model of premature aging?

A 34 year-old woman with Werner's syndrome has been studied in the light of the current concept that this disorder is a model of premature aging. Endocrine function assays revealed an abnormal glucose tolerance and in vivo insulin insensitivity after prednisolone, and ovarian failure. Immune function assays revealed hypo-responsiveness in skin tests for delayed hypersensitivity, a poorly sustained IgG anti-body response after immunization with flagellin, and a low count of colony-forming T lymphocytes in blood. Cultured fibroblasts had a very limited capacity to replicate in vitro, in comparison with donors of similar age and, moreover, 85% of glucose-6-phosphate dehydrogenase in the patient's cultured fibroblasts was heat-stable at 60 degrees C compared with 100% for a healthy control. Cell receptors (for insulin) were examined by insulin binding to isolated fat-cells, with the finding that fat-cells were abnormally large for the patient's size, and their receptor density was low. The findings from the study point to a genetic defect in Werner's syndrome which, in its effect on particular tissues, may simulate features of aging, but the disease is not a true model of premature aging.