MODY (Mature-Onset Diabetes of the Young)
- Autosomal dominant inheritance.
- Onset typically before age 25.
- Often misdiagnosed as type 1 or type 2 diabetes.
- Subtypes (e.g., HNF1A, HNF4A, GCK) require specific management (e.g., sulfonylureas for HNF1A, no treatment for GCK-MODY with mild hyperglycemia).
- Rationale: Genetic basis necessitates tailored therapy.
- Neonatal Diabetes Mellitus (NDM)
- Diagnosis before 6 months of age.
- Permanent or transient forms (e.g., KCNJ11, ABCC8 mutations).
- Transient NDM may resolve, but permanent NDM requires lifelong insulin.
- Rationale: Genetic testing is critical for management.
- Ketosis-Prone Diabetes (KPD)
- African American/Asian heritage common.
- Presents with DKA but may achieve remission off insulin.
- Associated with obesity, insulin resistance, and b-cell dysfunction.
- Rationale: Distinct from type 1/2; requires careful monitoring for relapse.
- Idiopathic Type 1 Diabetes
- Insulinopenia, DKA risk, no autoantibodies.
- Rare; diagnosis of exclusion.
- Rationale: Lack of autoimmunity complicates classification.
- Other Genetic Forms
- Mitochondrial diabetes, Wolfram syndrome, etc.
- Rationale: Multisystem involvement necessitates interdisciplinary care.
Key Considerations:
- Genetic testing for atypical presentations.
- Avoid misdiagnosis leading to inappropriate therapy (e.g., insulin in GCK-MODY).
- Multidisciplinary approach for syndromic diabetes.
Source: ADA 2026 Standards of Care (Section 15, Diabetes Care 2026).