Type 1 diabetes may result from good genes beha...( WHAT: New research from Stanford U...),Health

WHAT: New research from Stanford University scientists suggests that type 1 diabetes, an autoimmune disease that develops in children and young adults, may not be due to bad genes but rather to good genes behaving badly.

Because type 1 diabetes typically runs in families, scientists have looked for inborn genetic errors or gene variants passed on from generation to generation. Although this search has failed to find a single type 1 diabetes gene, many candidate type 1 diabetes susceptibility genes have been identified. These susceptibility genes, located in a region known as the major histocompatibility complex (MHC), help the body distinguish its own cells and tissues from those that are foreign.

Studies in identical twins, however, reveal that the situation is more complicated: often one twin develops type 1 diabetes while the other twin remains disease-free. This pattern of good luck/bad luck led researchers at Stanford to examine whether genetically at-risk individuals respond differently to environmental stimuli. In some cases, the immune system will respond in a benign fashion, while in other cases it will begin an inflammatory response that can ultimately lead to diabetes. The critical difference between health and disease might thus reside not in an individual's genetic blueprint but in how those genes are "expressed"--that is, how the translation of genetic information into proteins or RNA is switched on and off.

In a study supported by the National Institute of Allergy and Infectious Diseases, (NIAID) part of the National Institutes of Health, the Stanford team, led by C. Garrison Fathman, M.D., studied differences in gene expression between two groups of mice. The first group, non-obese diabetic mice, spontaneously develop type 1 diabetes. The second group, mice genetically identical to the first group except for their MHC genes, do not develop the disease. The researchers looked at gene expression in three different tis
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