Introduction
Diabetes is growing exponentially around the world. It is a metabolic disorder affected by changes in lifestyle. There are different types of diabetes. Monogenic diabetes is one of the types of diabetes that differ from type I and type II diabetes. Monogenic diabetes occurs mainly due to mutations in a single gene.
What Is Diabetes?
It is a systemic condition that exhibits increased blood sugar. This may be because the pancreas is inefficient at producing enough insulin or does not produce any insulin at all. All age groups of individuals may be affected by diabetes.
Glucose comes from food, that is, carbohydrates. The glucose is carried through the blood to all the body's cells. Glucose from the blood reaches different destinations with the help of a hormone called insulin.
When the pancreas does not produce insulin properly, and the body does not use the glucose, it may increase its levels in the blood, causing high blood sugar (hyperglycemia).
There are different types of diabetes. Monogenic diabetes is one of them.
What Is Monogenic Diabetes?
Monogenic diabetes is a rare condition that affects a single gene. The gene instructs the cells to make proteins. The protein may not function properly in the cell due to the change that occurs in the gene. Generally, two genes, or a pair of genes, are present, and each one is inherited from each parent.
When the gene responsible for producing insulin gets affected due to mutation or change, proteins are involved, and the ability of insulin to lower blood glucose is affected. In this condition, mainly insulin production is affected. Insulin production is usually reduced, and an increase in blood glucose (sugar) levels can be observed.
What Are the Types of Monogenic Diabetes?
Monogenic diabetes is a rare condition due to a defective gene that may be transferred from either one or both parents. Sometimes, the mutation may occur suddenly, and this type of diabetes is seen even though the defective gene is not inherited from either of the parents.
In other types of diabetes, like type I and type II, multiple genes are affected, hence the term "polygenic, whereas, in monogenic diabetes, only one gene is involved.
There are two forms of monogenic diabetes
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Neonatal diabetes mellitus (NDM).
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Maturity-onset diabetes of the young (MODY).
NDM:
This condition occurs at 6-12 months of age. It is a rare condition among 1 in 400 000 infants in the United States (US). This condition is generally mistaken for type I diabetes. But the kind I usually have yet to see before six months.
NDM may be permanently present in half of the people affected by this condition and is called permanent neonatal diabetes mellitus (PNDM). The remaining people exhibit the transient state of NDM, hence called transient neonatal diabetes mellitus (TNDM).
MODY:
This condition occurs in adolescence or early adulthood. This condition is seen in 2% of people in the US aged 20 years and younger. This occurs due to gene mutations affecting insulin production and increasing blood sugar levels.
There may be damage to tissues, eyes, kidneys, nerves, and blood vessels. This condition may be confused with type I and type II diabetes. But in this condition, there is a family history of diabetes.
What Are the Symptoms of Monogenic Diabetes?
Symptoms depend on the type of monogenic diabetes.
NDM:
Symptoms of NDM include
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Frequent urination.
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Fast breathing.
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Increased ketones, lead to diabetic ketoacidosis.
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Less growth due to intrauterine growth restriction.
Symptoms of MODY include
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Presence of frequent urination.
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Presence of thirst and dehydration.
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Vision gets blurred.
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Skin infections are seen often.
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Infections related to yeast.
How to Diagnose Monogenic Diabetes?
Monogenic diabetes can be diagnosed through
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Testing for blood sugar levels.
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Genetic testing.
Genetic testing is done on blood and saliva samples to check for DNA. DNA is analyzed to check for any changes or mutations in the genes. This test is done because these types include syndromic diabetes, exhibit overlapping causative genes in MODY, and represent autosomal dominant diabetes. There are over 20 genetic causes of NDM.
Genetic testing is recommended for
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Those who are identified with diabetes before six months of age.
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Those diagnosed with diabetes in children and young adults, those having a family history, and those who do not exhibit features of type I and type II.
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Those having stable and mild fasting hyperglycemia without obesity.
There are more than 14 genes involved in causing MODY. The type of gene detected indicates the severity or mildness of MODY.
Tests are done to identify genes like
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HNF1A gene.
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Glucokinase gene.
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HNF4A gene.
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HNF1B gene.
Other tests done to identify MODY are
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Testing of antibodies related to type I diabetes is done. The antibody tested is anti-GAD antibodies or zinc transporter antibodies. These antibodies are at low levels in this condition.
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To check for C-peptide levels. This helps to know whether the body prepares insulin or not.
If a newborn exhibits symptoms of diabetes, genetic testing should be done. NDM is missed or misdiagnosed if genetic testing is not done.
How to Treat Monogenic Diabetes?
Treatment depends on the genetic mutation that occurred.
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Medications are given to control increased blood sugar.
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Insulin injections may be given to a few who require them.
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Some individuals may change their lifestyle by exercising regularly and eating healthy food.
This condition is treatable, but an exact diagnosis must be made before treatment.
Conclusion
Monogenic diabetes is a type of diabetes due to a genetic mutation in a single gene. This condition involves increased blood sugar levels. This may be confused with other types. Hence, it becomes important to know about monogenic diabetes, its types, causes, symptoms, diagnosis, and treatment. Knowing helps in identifying the disease early. This helps an individual seek help early from a healthcare provider. Early diagnosis helps achieve effective treatment. This, in turn, helps lead a good quality life.
