Building Competency in Diabetes Education THE ESSENTIALS

CHANGES ACROSS THE LIFESPAN| 4-9

Monogenic Diabetes Monogenic diabetes refers to a mutation in a specific gene of a person with diabetes, i.e. MODY has a mutation of gene HNF1A or gene GCK, neonatal diabetes has a mutation of GKCNJ11 and others (30). Clinicians who are unfamiliar with monogenic diabetes often misapply the term to any youth with diabetes who does not require insulin (4,31). There are at least 20 different phenotypes comprising monogenic diabetes, with the most common forms being MODY and neonatal diabetes (32,33). The clinical spectrum of monogenic diabetes, including MODY, is broad, ranging from asymptomatic hyperglycemia to a severe and acute presentation (4). MODY has been reported in all ethnic groups, but type 1 or 3 MODY is generally found in non-obese Caucasians who present with nonketonic asymptomatic hyperglycemia (32). Diagnostic genetic tests allow for confirmation of monogenic diabetes and guidance regarding treatment and clinical course (34). Although it is important to determine the differential diagnosis, the patient who presents with metabolic decompensation will initially be treated with insulin and then may be weaned to oral medications if type 2 or monogenic diabetes is determined (8). The international society of pediatrics and adolescent diabetes suggests that the possibility of other types of diabetes should be considered in the youth who has (4): • An autosomal dominant family history of diabetes. • Associated conditions, such as deafness, optic atrophy or syndromic features. • Marked insulin resistance or requiring little insulin outside the partial remission phase. • A history of exposure to drugs known to be toxic to beta cells or cause insulin resistance.

Genetic testing for neonatal diabetes (onset <6 months of age) should be performed as transition from insulin to sulphonylurea treatment may be possible.