Table 2.

Familial diabetes diagnosed, or undiagnosed due to mild hyperglycaemia

Gene/protein	Clinical picture	Number of cases described	Median age at diagnosis in weeks (range)	Family history reflected by inheritance	Other clinical features	Other tests		Treatment
						Glucose at presentation in mmol/l Median (range)	OGTT
Familial diabetes diagnosed
HNF-1α	MODY3	197	14 (4–18)	Dominant	Hyperglycaemia is rapidly progressive with age	17 (11–26)	Large increment (0 h–2 h usually >5 mmol/l)	Diet > low dose of sulfonylurea
					Low renal threshold > glucosuria
					Sensitive to sulfonylurea
HNF-4α	MODY1	22	17 (5–18)	Dominant	Hyperglycaemia is rapidly progressive with age	15 (9–20)	Large increment (0 h–2 h usually >5 mmol/l)	Low dose of sulfonylurea
					Normal renal threshold
					Sensitive to sulfonylurea
					Reduced levels of apoAIII, apoCIII, and triglycerides
Other unusual causes: IPF1 (MODY4), NeuroD1 (MODY6), CEL (MODY7)
Familial diabetes undiagnosed due to mild fasting hyperglycaemia
Glucokinase (GCK, heterozygous)	MODY2	152	10 (0–18)	Dominant	Hyperglycaemia is mild (fasting 5.5–8 mmol/l)	11 (5.5–16)	Small increment (0 h–2 h usually <3.5 mmol/l)	No treatment
				(The mild hyperglycaemia might not have been diagnosed in relatives/parents)	Hyperglycaemia is only slowly progressive with age> usually diagnosis is by incidental finding
					Normal renal threshold