General information about other types of diabetes

While the majority of patients with diabetes have either type 1, type 2 or gestational diabetes, there are other uncommon types or causes of diabetes with specific underlying defects or disease processes (see Other types of diabetes and conditions causing hyperglycaemia).
Figure 1. Other types of diabetes and conditions causing hyperglycaemia.

[NB1]

diabetes secondary to pancreatic disorders (eg pancreatitis, cystic fibrosis, haemochromatosis, pancreatic carcinoma)

monogenic diabetes (eg GCK-MODY, HNF-1alpha-MODY, HNF-4alpha-MODY, HNF-1beta-MODY) [NB2]

drug-induced hyperglycaemia (eg glucocorticoids, antipsychotics, antiretrovirals, immunosuppressants)

genetic defects in insulin action (eg type A insulin resistance, leprechaunism)

endocrinopathies (eg acromegaly, Cushing syndrome)

congenital infections (eg congenital rubella, cytomegalovirus)

uncommon but specific forms of immune-mediated diabetes (eg ‘stiff-man’ syndrome, anti–insulin receptor antibodies)

other genetic syndromes sometimes associated with diabetes (eg Down syndrome, Wolfram syndrome, Turner syndrome, myotonic dystrophy)

Note:

MODY = maturity onset diabetes of the young

NB1: Diagnosing and managing secondary hyperglycaemia and uncommon types of diabetes can be complex—seek expert advice.

NB2: Some adults may have been misclassified when first diagnosed—see monogenic diabetes for further information.

Consider an alternative cause of hyperglycaemia or diabetes when:

  • the clinical picture is unusual for either type 1 or type 2 diabetes
  • a patient is not responding to treatment as expected
  • there are other features of a syndrome or alternative pathology (eg clinical features of acromegaly in a patient with hyperglycaemia).

However, routine testing for uncommon types or causes of diabetes is not recommended.

Note: Routine testing for uncommon types or causes of diabetes is not recommended.

Diagnosing and managing secondary hyperglycaemia and uncommon types of diabetes can be complex—seek expert advice.