Monogenic diabetes: does making the diagnosis matter?

Ceclia Chi, Jenny E Gunton



Monogenic diabetes – diabetes due to a single gene mutation – is often misdiagnosed as type 1 or type 2 diabetes. The significant differences in treatment needs and responses in patients with the various types of monogenic diabetes emphasise the need for an accurate diagnosis.

Key Points

  • Monogenic diabetes (maturity onset diabetes in the young; MODY) should be considered as a diagnosis in the young person diagnosed with ‘atypical’ type 1 or type 2 diabetes.
  • Insulin may be ceased in patients with certain types of MODY and be replaced by sulfonylurea monotherapy, often to the great relief of patients.
  • Monogenic diabetes due to glucokinase (GCK) gene mutation usually remains mild and nonprogressive and, unless more significant glucose elevation develops (e.g. glucose levels greater than 11 mmol/L postprandially), may be controlled by lifestyle measures alone.
  • Patients with gestational diabetes should be referred for specialist review as treatment of patients with diabetes due to GCK mutation may adversely affect the fetus if the fetus has inherited this mutation.

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