Monogenic diabetes is a rare form of diabetes that differs from both Type I and Type II diabetes. It is caused by a mutation in a single gene. If one parent carries this mutation, their children have a 50% chance of inheriting it. Although monogenic diabetes accounts for about one in every fifty cases of diabetes, it is often misdiagnosed or mistaken for the more common types (Type I or Type II diabetes). Because monogenic diabetes is much rarer, accurate genetic testing is critical for proper diagnosis.
The primary phenotypes of monogenic diabetes include MODY (Maturity Onset Diabetes of the Young), which typically manifests before the age of 25, neonatal diabetes, and other very rare syndromic forms.
Extensive studies have identified numerous genetic variants linked to diabetes. Genetic testing is particularly beneficial for diagnosing certain forms of diabetes caused by single-gene defects. For example:
Patients with MODY are often misdiagnosed as having either Type I or Type II diabetes due to their similar clinical characteristics and the general lack of awareness about the condition. Misdiagnosis can lead to inappropriate treatments—such as unnecessary insulin or sulfonylurea therapy—and result in avoidable complications.
The genetic test involves:
This test is essential for accurately classifying the type of diabetes. Early and precise diagnosis of monogenic diabetes at the clinical level reduces the risk of inappropriate or absent treatment, which is crucial for effective disease management.
If high blood glucose levels remain untreated for an extended period, they can lead to complications such as blindness, limb amputations, and an increased risk of heart attacks.
Most patients diagnosed early with monogenic diabetes can manage their condition effectively with oral medications or dietary modifications to control blood sugar levels, rather than undergoing frequent and unnecessary insulin injections.
The test can also detect whether children have inherited the affected gene and are likely to develop monogenic diabetes, typically before the age of 30. Understanding and accurately diagnosing these rare forms of diabetes is extremely important for ensuring appropriate early intervention and management.
