Maturity onset diabetes of the young (MODY) refers to any of several hereditary forms of diabetes caused by mutations in genes (inherited from either parent) disrupting insulin production.
MODY is often referred to as “monogenic diabetes” to distinguish it from the more common types of diabetes like type 1 and type 2, which involve more complex combinations of causes involving multiple genes (i.e., “polygenic”) and environmental factors.
MODY 2 and MODY 3 are the most common forms. The severity of the different types varies considerably, but most commonly MODY acts like a very mild version of type 1 diabetes, with continued partial insulin production and normal insulin sensitivity. MODY is not type 2 diabetes in a young person, as might erroneously be inferred from the name.