Abstract for presentation at 11th International Congress of Human Genetics

Gestational diabetes mellitus (GDM) is an elevation of plasma glucose that occurs in 5% of pregnancies in Australia. It is likely that the same genetic predisposition to the late onset Type 2 diabetes underlies GDM. Many women who experience GDM go on to develop Type 2D later in life. In GDM, subjects are young and parents are usually available. This makes study of GDM more powerful than Type 2 diabetes.
We have chosen a small number of genetic markers that have shown evidence of linkage to diabetes susceptibility genes in other studies and tested them in 100 sibpairs who experienced GDM. One of these regions from chromosome 10 shows highly significant increased allele sharing in a subset of 50 pairs where waist-to-hip ratios were similar in the sibs. A region on chromosome 1 shows suggestive evidence of linkage and 6 other regions show no evidence of a gene involved in GDM in the region.
At least some regions with genes contributing to Type 2 diabetes also contain genes contributing to GDM. They are likely to be the same genes.. The strong evidence for genes contributing to GDM on chromosome 10 also indicates that GDM may be a pathological state and not just the tip of a normal distribution of glucose levels in pregnancy. The relationship of GDM to Type 2 Diabetes can be exploited to help solve the major medical problem of type 2 diabetes.