Comparison of maturity onset diabetes of the young subtypes
| MODY mutation | HNF1α (previously MODY3) | GCK (previously MODY2) | HNF4α (previously MODY1) |
|---|---|---|---|
| Estimated frequency | 52% | 32% | 10% |
| Chromosome affected | 3 | 7 | 20 |
| Defect | Progressive reduced insulin secretory response to glucose | Higher threshold for glucose stimulated insulin | Regulates activity of HNF1α therefore also show abnormal insulin secretory response to glucose |
| Clinical features | Low renal threshold for glucose (glycosuria) | Mild, stable and asymptomatic; hyperglycaemia often found incidentally | Normal renal threshold for glucose |
| Risk of microvascular/macrovascular disease | Yes | Not observed | Yes |
| Optimal treatment | Sulphonylureas, but may progress to insulin | Not required; will need close monitoring during pregnancy | Sulphonylureas, but may progress to insulin |
HNF1α = hepatocyte nuclear factor-1-alpha; GCK = glucokinase; HNF4α = hepatocyte nuclear factor-4-alpha.