Types of MODY
The commonest types of Maturity Onset Diabetes of the Young (autosomal dominant / monogenic diabetes) accounting for nearly 90% of cases.
|full name||Hepatic Nuclear Factor 1 Alpha||glucokinase||Hepatic Nuclear Factor 1 Beta||Hepatic Nuclear Factor 4 alpha.||Insulin promoter factor-1||Neurogenic differentiation 1 gene|
|how common||Accounts for 70% of cases.||30-70% of cases||5-10% of cases.||5-10% of cases.||< 1% of cases.||Very rare.|
|pathology||Changes gene leads to reduced insulin production.||An enzyme that phosphorylates glucose and a 'sensor' that triggers response to hyperglycaemia. More than 130 gene mutations described.||Renal Cysts & Diabetes. Familial cystic kidney syndrome associated with mutations.||Regulates HNF1A gene so the disease is similar.||A homeodomain transcription factor required for pancreas development.||regulates expression of the insulin gene|
|clinical course||Progressive usually from early adulthood. Low renal threshold for glucose.||Mild fasting hyperglycaemia (5.5 - 8 mmol/l) throughout life. Small rise with glucose load - usually less than 3 mmol/l rise with OGTT. Complications are rare.||Unexplained renal cystic disease. Early onset diabetes. Genital tract mutations. Gout.||Progressive usually from early adulthood. Low renal threshold for glucose.||may contribute to early- or late-onset diabetes as part of a polygenic background||variable|
|management||Sensitive to sulfonylureas||Treatment has very little effect. Treatment during pregnancy may be required. Avoid obesity and its associated risk of Type 2 diabetes.||Usually does not require insulin.||Sensitive to sulfonylureas||variable||May require insulin.|
MODY accounts for 1-2% of apparent Type 2 Diabetes (and some apparent Type 1 Diabetes) and is a clinically heterogenous group. Over 1000 genetic abnormalities have been identified.
Sources: http://www.diabetesgenes.org/content/maturity-onset-diabetes-young, OMIM http://omim.org/entry/606391