The Common Subtypes
Reviewed by CDE Mehandi Sharma · Updated
MODY is not one condition. Which gene is involved determines how your diabetes behaves and how it should be treated, so the subtype is the useful piece of information.
GCK-MODY and HNF1A-MODY together account for more than 80% of MODY cases, with HNF4A-MODY making up much of the remainder.
| Subtype | Typical picture | Usual treatment |
|---|---|---|
| GCK (MODY2) | Mild, stable raised fasting glucose; usually no symptoms; does not worsen with age | Usually none outside pregnancy |
| HNF1A (MODY3) | Young, lean; mildly raised fasting glucose with large rises after meals; progressive | Low-dose sulfonylurea |
| HNF4A (MODY1) | Similar to HNF1A, plus high birth weight and low newborn blood sugar | Low-dose sulfonylurea |
| HNF1B | Diabetes with kidney abnormalities, often cystic kidney disease | Varies; kidney care alongside |
Worth noticing: the subtype mix differs by population. In European cohorts GCK is often the most common. In an Asian Indian clinic study of confirmed MODY, HNF1A accounted for 61.7%, HNF4A for 29.4% and ABCC8 for 8.8% — with no GCK cases in that group.
That matters because the two dominant Indian subtypes are precisely the ones that respond well to a specific tablet.