Maturity-onset diabetes of the young, or MODY, is a form of monogenic diabetes that is caused by mutations in a number of different genes. Each different mutated gene causes a slightly different type of diabetes.
MODY is typically diagnosed in late childhood, adolescence, or early adulthood. However, it has been known to develop in adults as late as their 50s. Many people with MODY are misdiagnosed as having type 1 or type 2 diabetes. However, a diagnosis of MODY could change the course of treatment and could help to identify other family members with MODY.
How many people have MODY?
It is believed that up to 2 percent of all diabetes cases are due to MODY.
Who should be tested for MODY?
- A diabetes patient who is part of a family with three or more consecutive generations affected by diabetes
- A diabetes patient with stable, mildly elevated blood sugars, often found incidentally during a routine check-up
- A “type 1″ diabetes patient who has negative blood testing for autoantibodies, typically done at the time of diabetes diagnosis (antibodies typically tested include one or more of the following: GAD65, islet cell or ICA, IA-2, insulin, ZnT8)
- A “type 1″ diabetes patient who generates a significant amount of insulin years beyond diagnosis (detectable blood levels of c-peptide, proinsulin, and/ or insulin)
- A “type 2″ diabetes patient who is normal weight or not significantly overweight and shows no signs of insulin resistance
- Diabetes paired with pancreatic insufficiency (the digestive role of the pancreas is impaired with symptoms such as diarrhea and gas)
- Individual or family history of diabetes paired with developmental kidney disease or abnormalities of the kidney (especially cysts). The urinary system and reproductive organs may also be abnormally formed.
Will treatment change if I have MODY?
That depends on the type of MODY. MODY caused by mutations in the HNF1A or HNF4A genes often, though not always, responds well to low doses of sulfonylureas. MODY due to mutations in GCK typically requires no treatment at all. The best treatment for other MODY types is unclear and varies from one person to the next.
If I have MODY, can I pass it on to my children?
MODY is an autosomal dominant disease. That means that each child will have a 50% chance of inheriting the gene mutation that can cause MODY. It also means that if you have MODY and your siblings or parent have diabetes, they are very likely to have MODY too.