What is Monogenic Diabetes?
Monogenic diabetes is a rare form of diabetes that occurs due to a change to a single gene and is known to be different from type 1 and type 2 diabetes. This type of diabetes often requires genetic testing for diagnosis. Mostly, the cases of monogenic diabetes are inherited. In monogenic diabetes, insulin production is reduced that leads to an increase in blood sugar levels.
Monogenic diabetes is of two types:
- Neonatal diabetes mellitus (NDM) that occurs in newborns and infants.
- Maturity-Onset Diabetes of the Young (MODY), which is more common and occurs in adolescents and young adults.
How is Monogenic Diabetes Different from Type 1 and Type 2 Diabetes?
Monogenic diabetes occurs due to mutation in a single gene while type 1 and type 2 diabetes are polygenic and occur due to mutation in multiple genes.
Type 1 diabetes requires insulin treatment whereas monogenic and type 2 diabetes do not always require insulin.
Insulin treatment may be needed in a person with monogenic diabetes as he gets older.
Causes of Monogenic Diabetes
Monogenic diabetes is caused due to changes in a single gene. It is inherited from just one parent called an autosomal dominant gene. Sometimes the change or mutation are not inherited and happen spontaneously. Monogenic diabetes can be temporary or a lifelong condition.
Symptoms of Monogenic Diabetes
Knowing the symptom of both types of monogenic diabetes help in getting timely proper treatment.(1)
The symptoms are as follows:
Maturity onset diabetes of the young: Frequent urination, dehydration, thirst, blurry vision, recurrent skin infections, and recurrent yeast infections.
How is Monogenic Diabetes Diagnosed?
To diagnose monogenic diabetes, blood sugar and genetic testing are done. Genetic testing involves taking samples from blood or saliva. DNA is examined to look for the changes in the genes.
According to the National Institute of Health, genetic testing is recommended in the cases where:(1)
- Diabetes is diagnosed before 6 months of age.
- Children or young adults are diagnosed with diabetes.
- A person has stable and mild fasting hyperglycemia, without obesity.
There are 14 different genes associated with maturity-onset diabetes of the young.(2) The type of gene detected can indicate the severity of the condition.
Tests are done to detect the following genes:
- HNF4A gene (MODY 1)
- Glucokinase gene (MODY 2)
- HNF1A gene (MODY 3)
- HNF1B gene (MODY 5)
There are a few other tests that can be done to diagnose maturity-onset diabetes of the young.(3) According to an overview of 2020 the clinical screening approaches for maturity-onset diabetes of the young include:
- Performing antibody tests for type 1 diabetes such as anti-GAD antibodies, or zinc transporter antibodies.
- Checking the level of C-peptide.
- If a newborn child shows the symptoms of diabetes, it is recommended to check for monogenic diabetes.
Treatment for Monogenic Diabetes
The treatment of monogenic diabetes depends on the genetic mutation cause, its type, and severity.
Some cases of monogenic diabetes can be managed with diet and exercise while a few may require insulin.
Sulfonylurea drug can be used as it helps the body release more insulin into the blood.
In neonatal diabetes, insulin might be required in the beginning. It mostly disappears at about 12 weeks of age.
If any symptom of diabetes is noted in the child or teenager, it is good to see a doctor. It is more important if there is a family history of diabetes. Speak with the doctor regarding the risk factors and how to keep things managed in long run.
Monogenic diabetes is treatable, but it is important to get an accurate diagnosis, which can be achieved by medical history and genetic testing. Knowledge of symptoms can be helpful in the case of infants and young adults. A doctor can be the best person to help reach a solution to the problem and suggest the best treatment.