It was a misconception until the last few years that diabetes only affects the person after a certain age. However, the studies have shown the onset of diabetes in a younger generation as well. There are various hereditary forms of diabetes caused due to the mutations in a gene. They are called MODY – Maturity–Onset Diabetes of the Young. It is said that approximately 5% of all diabetes cases are MODY. People of Asian Indian descent may have greater chances of MODY compared to the others.
MODY is a group of around 6 different genetic defects that damage response to the insulin. Different types of defects have different symptoms based as well as different therapies.
MODY is caused because of the mutations in an autosomal dominant gene that disrupts the insulin production. Whereas type 1 & type 2 diabetes is a result of multiple factors and genes. Some of these types can be treated or managed with changes in lifestyle, some get benefits from sulfonylureas while others need insulin.
HNF1 – alpha, HNF4 – alpha, HNF1- beta, Glucokinase are some of the types of the MODY Diabetes.
There are differences between how the different versions of MODY manifest. But here are some of the traits several forms of MODY have in common:
- People with one of the forms of MODY that primarily affect the secretion of insulin in response to a meal may have near-normal fasting blood sugar test readings and very high post-meal blood sugars.
- The age of onset of diabetes in at least one form of MODY is significantly younger if it was the mother who passed on the gene; may be because of the exposure to high blood sugars in the womb affects the expression of the MODY gene in the offspring.
- It is a myth that MODY only affects people under 25. It may develop at any age up to 55.
- Women with MODY are often first diagnosed during a first pregnancy. Though not obese, they develop gestational diabetes very quickly.
- People with MODY often are not insulin resistant.
- Some versions of MODY respond very well to drugs that stimulate insulin secretion.
- In one common form of MODY, fasting blood sugar is normal, but insulin secretion begins to fail as blood sugars go over 144 mg/dl.
- People with some forms of MODY often have subtle or more obvious congenital kidney defects and may even have signs of kidney disease before they are diagnosed with diabetes.
A person diagnosed with Type 1 Diabetes might have MODY if:-
- They had diagnosed of diabetes before 6 months of age.
- They have a parent with a family history of diabetes. (Only 2% to 4% of people with Type 1 have an affected parent).
- They have detectable insulin production three years or more than that after the diagnosis.
- They have no immune antibodies to their islet cells, especially at diagnosis.
Most of the times, MODY is misdiagnosed as type 1 or type 2 diabetes because there are no distinct symptoms to distinguish MODY from other types of diabetes. This is where genetic testing plays an important role. Genetic test offers definitive diagnosis for the mutations linked to the disorder.
About the MODY test
MODY is caused by mutations in any one of more than 10 genes while over 20 genes have been associated with monogenic neonatal diabetes. Depending on the genes involved, the course of treatment varies.
The genetic test is very simple – It involves collecting either a blood or saliva sample and sending it to a laboratory for testing. The sample is used to make DNA and gene sequencing is performed. The order of bases in a person undergoing genetic testing is compared to the correct order for each gene being tested. Mutation is considered if there is a difference in the pair. However, not all mutations will actually cause diabetes. Hence, it is very important to check with the expert if results of genetic testing are really the cause of diabetes.
Because of the high level of precision, genetic testing turns to be very helpful for the patients and helpful for their better future.