Maturity onset diabetes of the young (
MODY) is characterized by youth-onset diabetes that is inherited in an autosomal dominant (monogenic) pattern. Classic
MODY accounts for less than 5% of cases of childhood diabetes in Caucasians, presents prior to age 25 years, is nonketotic, and may not require
insulin treatment. A variant form of
MODY that lacks a clearly defined genetic basis occurs in African Americans [atypical
diabetes mellitus (ADM)] clinically presents more acutely and is initially
insulin requiring. To date, five molecular causes of classic
MODY have been identified: hepatocyte nuclear factor-4 alpha (HNF-4 alpha;
MODY1),
glucokinase (
MODY2), hepatocyte
nuclear factor-1 alpha (HNF-1 alpha;
MODY3),
insulin promoter factor-1 (IPF-1, MODY4), and hepatocyte
nuclear factor-1 beta (HNF-1 beta; MODY5).
MODY is studied as a model of beta cell hypofunction and modest insulinopenia. Clinical recognition of ADM is important for patient management to avoid
confusion with
type 1 diabetes mellitus.