Unlike some diseases that are controlled by a single gene, almost 20 known genes can be involved in developing type 1 diabetes. The complex interaction among them can affect whether a child is diabetic. The American Diabetes Association reports that the odds of having a diabetic child depend upon the health, age and gender of the affected parent. The odds that a child of a man with type 1 diabetes will be diabetic are 1 in 17. The odds that child of a woman with type 1 diabetes will be diabetic are 1 in 25 if the mom is under 25, and 1 in 100 if the mom is over 25.
SUMO-4
The Juvenile Diabetes Research Fund explains that a gene called SUMO-4 is involved in a child's susceptibility to type 1 diabetes. SUMO-4 is involved in determining the intensity of the immune response. A defective form of this gene increases the reactivity of the immune system so that the body overreacts to various environmental triggers. This defective gene may increase the likelihood that the immune system will attack cells that produce insulin.
HLA Region
The human leukocyte antigen or HLA region is a group of genes that reside on chromosome six. According to GeneticHealth.com, variants -- also called alleles -- of two genes, DR and DQ, in the HLA region account for 40 to 50 percent of the genetic basis of diabetes.
Two particular alleles of DR are closely associated with type 1 diabetes. Among type 1 diabetics, 95 percent have one of these alleles. About 30 percent of people with type 1 diabetes have both. Only 50 percent of healthy people have one of these alleles; 1 to 2 percent of healthy people have both.
People who have inherit the risky DR alleles also inherit a form of the DQ gene that places them at higher risk for the disease.
Insulin Gene
The gene responsible for producing insulin does not appear to be related to type 1 diabetes. However, GeneticHealth.com reports that gene sequences near the insulin gene determine how much insulin is made. Some variants of these sequences can increase susceptibility to the disease. Since the length of this region can vary, it is referred to as VNTR or variable number of tandem repeats.
