MODY (Maturity-Onset Diabetes of the Young) is a monogenic form of diabetes, typically presenting before age 25, with an autosomal dominant inheritance pattern.
- Key Features:
- Early onset: Diagnosis often occurs before age 25, but symptoms may be mild, leading to delayed diagnosis.
- Non-insulin-dependent: Initially managed without insulin, though some subtypes may require it later.
- Strong family history: Autosomal dominant inheritance is common, with affected family members across generations.
- Subtypes (based on genetic mutations):
- HNF1A (MODY 3): Most common; associated with high sensitivity to sulfonylureas.
- HNF4A (MODY 1): Often presents with low birth weight and liver dysfunction.
- GCK (MODY 2): Mild hyperglycemia; often no treatment needed.
- Other subtypes (e.g., PDX1, HNF1B): Less common; may present with renal or liver abnormalities.
- Diagnosis:
- Genetic testing is confirmatory; clinical criteria include early-onset diabetes, strong family history, and absence of autoimmunity (negative islet autoantibodies).
- Management:
- Subtype-specific: E.g., sulfonylureas for HNF1A, diet/exercise for GCK-MODY.
- Avoid insulin if possible (except in severe cases or pregnancy).
- Rationale: MODY is distinct from type 1/2 diabetes due to its genetic basis and unique treatment responses. Early diagnosis prevents unnecessary insulin use and optimizes therapy.