Most people are familiar with diabetes in a general sense. They know that someone with diabetes either has type 1 diabetes or type 2 diabetes and that one of them is an autoimmune disease and the other is largely caused by lifestyle habits or environmental factors. These are considered polygenic forms of diabetes.1 What people aren’t aware of—even a lot of people diagnosed with diabetes themselves—is that there is another, more rare, form of diabetes. This type of diabetes is called monogenic diabetes. In this article, we’ll cover everything you need to know about monogenic diabetes, including how it’s diagnosed and treated.
What is Monogenic Diabetes?
To begin, it’s important to differentiate monogenic diabetes from polygenic diabetes—type 1 and type 2 diabetes. Monogenic diabetes is a rare form of diabetes that results from a single gene mutation,1 while polygenic diabetes results from gene mutations in one or more genes. Because of this, monogenic diabetes is rare and only accounts for about 1% to 4% of all cases of diabetes in the United States.1 Monogenic diabetes can either be inherited from one or both parents or occur spontaneously, but both mutations reduce your body’s ability to naturally produce insulin.1 Most cases of monogenic diabetes are genetically inherited and thus spontaneous monogenic diabetes is one of the rarest forms of diabetes.
Monogenic diabetes mostly affects young people and causes the body to produce less insulin than what’s needed.2 Only in extremely rare circumstances does monogenic diabetes cause severe insulin resistance.2 Because of the lack of research and education about monogenic diabetes, most cases are incorrectly diagnosed as type 2 diabetes.1 However, correctly diagnosing monogenic diabetes is crucial for the proper care and treatment.
Diagnosing Monogenic Diabetes
Since most cases of monogenic diabetes are wrongly diagnosed, it’s important to talk to your doctor about your options if you suspect you or a loved one may have any form of diabetes. Again, as we said, proper diagnosis is the best way to ensure proper care and treatment. There are a number of different ways to test for monogenic diabetes including the following:
Blood Test
As with testing for type 1 or type 2 diabetes, a blood test is needed to determine blood glucose levels and reactions. Using a blood test for monogenic diabetes will allow your doctor to see how much insulin the body is currently making.2 They will also be able to see if there are any auto-antibodies being made in your blood, which would indicate an autoimmune disorder of type 1 diabetes.2 If there are no auto-antibodies, but your doctor finds that there is a lower than usual amount of insulin being produced, they should continue on to other tests instead of simply diagnosing type 2 diabetes.
Clinical Factors
Your doctor should also look at clinical factors that could suggest monogenic diabetes. Some of these include being diagnosed with diabetes within the first 6 months of life, when there is a family history of diabetes, when there are features of diabetes that don’t fall into the typical “type 1” or “type 2” category, and when a person has a stable, mild fasting hyperglycemia, even if they’re in a normal weight category.1 Similarly, genetic testing will be beneficial if someone in your family has diabetes, but are a normal weight or if you belong to certain ethnic groups that are more at risk for diabetes.2
Genetic Testing for Monogenic Diabetes
Since most forms of monogenic diabetes are inherited, and type 2 diabetes is largely environmental, genetic testing is a good way to determine whether or not your glucose levels are due to monogenic diabetes or type 2 diabetes. Genetic testing is recommended when a person has one or more of the clinical factors discussed above.
Genetic testing will show your doctor whether or not you have the specific gene for either type of monogenic diabetes. If you have the gene but don’t currently show any symptoms, making healthy lifestyle changes can reduce the chances of the gene becoming active.
Different Forms of Monogenic Diabetes
When diagnosing monogenic diabetes, there are two different forms that your doctors will look for. There is neonatal diabetes mellitus (NDM) and maturity onset diabetes of the young (MODY).
Neonatal Diabetes Mellitus (NDM)
Neonatal diabetes mellitus is a type of diabetes that occurs in the first 6 to 12 months of life.1 It’s extremely rare, but still occurs and should be considered if your newborn starts to show any symptoms. The problem is that symptoms are similar to type 1 diabetes and many people assume that’s what it is since type 1 diabetes is an autoimmune disease. However, type 1 diabetes rarely, if ever, occurs before 6 months.1 When diabetes occurs this early, it’s likely NDM and needs to be addressed as NDM is treated differently than type 1 diabetes. Each case of NDM is a different from the next, so make sure your infant is tested for specific gene mutations to better treat their monogenic diabetes.
Maturity Onset Diabetes of the Young (MODY)
The other type of monogenic diabetes is called maturity onset diabetes of the young. This type generally occurs in adolescence or early adulthood and accounts for only 2% of all cases of diabetes in the US under 20 years old.1 In MODY, the pancreas’ ability to produce insulin is limited and therefore leads to high blood glucose levels.1 Similar to NDM, the clinical features that are presented will make a difference as to how MODY is treated. Most people who are diagnosed with MODY are not overweight or obese, which is one thing that sets it apart from type 2 diabetes patients.
- HNF1-alpha Gene (MODY 3) – this type of MODY is one of the most common types and is best treated using sulfonylurea agents.3
- HNF1-beta Gene (MODY 5) – this type is more severe and requires insulin to ensure that kidney cysts or uterine abnormalities don’t form over time.3
- Glucokinase Gene (MODY 2) – more often than not, this form of MODY is so mild that it doesn’t actually require treatment and does not present the same complications as other types of diabetes.3
Living with Monogenic Diabetes
As outlined above, each type of monogenic diabetes has a specific treatment, so it’s important to understand which type you, or your child, has. To do this, make sure that you undergo genetic testing with your doctor. There are both dominant and recessive genes of each, which your doctor will be able to discuss with you in more detail. Some forms of monogenic diabetes need sulfonylurea, others need insulin, and some might not need any medication at all.1 As a general rule of thumb, the treatments for NDM and MODY are as follows.
Treatment for NDM
If you have a child that’s been diagnosed with neonatal diabetes mellitus (NDM) your doctor will work towards finding the originating source of the monogenic diabetes. Each case is specific to the cause—certain types of NDM diagnosis require sulfonylurea for treatment and others require insulin.2 Even though condition is required at the start, some cases disappear around 12 weeks of age and don’t need treatment anymore.2
Treatment for MODY
The treatment for maturity onset diabetes of the young is similar to NDM in that treatment depends on the case. Some people don’t need medications at all and only require maintenance through diet and exercise while others need sulfonylurea or insulin.2 This is why it’s so important to work with your doctor to determine what the best treatment plan is for your monogenic diabetes.
Conclusion
If you suspect that you or a loved one has either form of monogenic diabetes, the best thing you can do is educate yourself. The more you learn, the better you’ll be able to manage your monogenic diabetes. As new medical approaches and therapies continue to develop, you’ll find new ways to gain control over your diabetes and live a healthy life. One way to do this is through Byram Healthcare’s Caring Touch At Home™ Program. This program combines exceptional customer service with top-of-the line brand name products to make sure that your needs are covered while reducing out of pocket expenses. The Caring Touch At Home™ Program combines convenience, affordability, and choice to deliver extensive service and support to everyone living with diabetes.
If you or someone you love has been diagnosed with monogenic diabetes, it’s important to get the treatment and care that you need. That’s why Byram Healthcare has a Diabetes Center of Excellence—a one source, total solution for diabetes care. We carry a full line of products including testing supplies, continuous glucose monitors, test strips, lancets, insulin pumps, and more. Paired with clinical and educational resources, Byram Healthcare is here to give you all of the support you need. Head over to our website today to browse our available selection, find resources, and learn more about our Caring Touch At Home™ Program.
Sources:
2https://www.hormone.org/diseases-and-conditions/diabetes/monogenic-diabetes
3https://beyondtype1.org/what-is-monogenic-diabetes/
