What are the current thoughts regarding the etiology of type 1 diabetes mellitus (T1DM)? No one else in Rachel's family has diabetes—is this unusual? Are there any other findings in her family medical history that would be important to note?

Question

What will be an ideal response?

Answer 1

While the disease is multifactorial, about 85%-89% of people diagnosed with type 1 diabetes mellitus have one or more autoantibodies present, indicating it is an autoimmune disorder. The rate at which β-cells are destroyed varies from person to person, and this destruction is thought to be caused by a variety of factors. Genetics plays a role, as 40% of children with type 1 diabetes mellitus have the same haplotype, although many different genes contribute to its expression. Environmental factors may trigger this genetic predisposition, purportedly through a viral infection or allergic response. An increased need for insulin after β-cell destruction, as seen in acute illness or stress, seems in many cases to be the tipping point that leads to symptoms and diagnosis of the disease. A small portion of individuals diagnosed present with no known cause for the disease. This form of type 1 diabetes mellitus is called idiopathic type 1 diabetes.
Important factors from Rachel's family history to note would include that her mother has hyperthyroidism and her sister has celiac disease. Hyperthyroidism and celiac disease both have an autoimmune component in regard to their etiology. In fact, according to the pediatric nutrition care manual, 17-30% of children with diabetes also have thyroid disorders while anywhere from 1-16% of children with type 1 diabetes simultaneously have celiac disease. Rachel may have a genetic predisposition to these autoimmune disorders.