Background: Genetic factors are involved in the development of diabetes. We here evaluate the possibilities for a genetic diagnosis of diabetes.
Methods: This overview is based on a limited literature search in PubMed as well as our own experience.
Results and interpretation: Sequence variations in a number of genes and genomic regions result in an increased risk for development of type 1 and type 2 diabetes. With the exception of the HLA genes and their association with type 1 diabetes, these sequence variations each cause only a modest increase in diabetes risk. In contrast, disease-causing mutations can be identified in six genes associated with maturity-onset diabetes of the young (MODY). In most countries, MODY2 and MODY3 are the most frequent subtypes. Sulphonylurea may be the drug of choice when treating MODY3 because sensitivity for the drug is preserved even after long duration of diabetes. Neonatal diabetes is often caused by mutations in a component (Kir6.2) of the potassium channel of the beta cell. Patients can be managed on oral sulphonylurea with sustained metabolic control rather than on insulin injections.