Inherited Metabolic Disorders – Symptoms and Causes

An inherited metabolic disorder, also known as an inborn error of metabolism, is a group of genetic conditions that mainly affect the function of your metabolism. These are genetic or heritable disorders. Metabolism’s main task is to run a chemical process that converts food into energy and helps remove toxins from the body. Treatment of IEM includes certain changes to your diet and medicines that help your body have a better metabolism.

What is Inherited metabolism / Inborn error of metabolism (IEM)?

Inherited metabolism is also known as an inborn error of metabolism or hereditary metabolism, and this is the group of conditions that affect the ability to convert food into energy and remove the leftover waste and unhealthy substances from your body. Most people with inherited metabolic disorders have defective genes that mostly result in enzyme deficiency. The lack of a specific enzyme can create blockage in biochemical reactions, which can affect the normal reaction of the human body. However, inherited metabolism is a genetic disorder which mainly affects the metabolism pathway in your body.

What are the types of inherited metabolic disorders?

Inherited metabolic disorders of many types and most of the conditions get their names from the affected enzyme. Here are some of the most common types of affected metabolism:

Maple syrup urine disease:

When an amino acid builds up in your body and causes a damaged nerve, then it can be the reason for smelly pee (Urine) like maple syrup.

Peroxisomal disorder:

It is the same as Lysosomal storage disorder. It leads to toxins building up in the human body.

Metal metabolic disorder:

The human body contains small traces of metal in it; when the metal starts to build up to a toxic level, that build-up metal is harmful to your body. This includes hemochromatosis (excess iron levels) and excess copper levels in Wilson disease.

Lysosomal storage disorder:

It happen when your body is not able to throughout all the break down waste out of your body, it cause toxin to build up in your body. However, Lysosomal storage disorder includes Gaucherdisease, Hurler syndrome and Tay-Sachs disease.

Mitochondrial diseases:

When you eat food and the nutrition from food are not absorbed properly, due to which your body can’t able to produce the enough energy for you. That’s where the condition affects the functionality of many organs like liver, brain, kidneys and muscles, etc.

Urea cycle disorder:

When your body is unable to process ammonia by itself and it gets build up to toxic level in your blood.

Glycogen storage disease:

Sugar from the food you consume can’t get stored in your body properly, and that’s where you get low blood sugar.

Krabbe disease:

It is a progressive nerve damage, It also effects the development in young children, adults are occasionally affected.

Symptoms of inherited metabolic disorders

Symptoms of inherited metabolic disorders can vary depending on the metabolism problem a person has. Some of the common symptoms of inherited metabolic disorders include:

• Poor appetite
• Weight loss
• Abdominal pain
• Jaundice
• Lethargy (Low energy)
• Seizures
• Failure to gain weight or grow
• Vomiting
• Developmental delay
• Abnormal odour of breath, sweat, urine and saliva.

All these symptoms may suddenly comes or may process slowly over time. These symptoms can be brought on by dehydration, medication, minor illness, certain foods, or other factors. Inborn error of metabolism can show symptoms after few weeks of birth in many conditions. However, other symptoms of inherited metabolic disorders may takes years to develop.

What causes inherited metabolic disorders?

Inherited metabolism happen when a genetic mutation is happens when the cells divide and replicate during fetal development. There are various kinds of possible genes and their type of inherited metabolism varies.

When you eat, certain type of genes in your body will give instructions for proteins to perform chemical reaction for your metabolism. Those special proteins are known as enzymes, that produce these chemical reactions.

When a person is suffering from inherited metabolic disorders, the enzymes won’t have the instructions they need for the metabolism, which is is the main reason for some specific inherited metabolism in a person’s body.

Who can be affected by inherited metabolism?

Inherited metabolic disorders can affect anyone, as it is a condition that happens due to genetic change in DNA. Each inherited metabolism is of different type of metabolism disorder and has a different form of inheritance. A person can be at higher risk of inherited metabolic disorders if someone from his/her family has this condition.

How does inherited metabolic disorders affect a person’s body?

Inherited metabolism will affect a person’s body in a way where the ability to process one of these following form of component from the beverages or food that you eat or drink.

• Protein.
• Sugar.
• Carbohydrates.
• Fat.

In result to this, system within your body can cause changes to your development, ability to interact to others and body growth. The symptoms of the inherited metabolic disorders can affect multiple organs in a person’s body.

Diagnosis and test for inherited metabolic disorders

How are inherited metabolic disorders diagnosed?

Inherited metabolic disorder in some cases can be diagnosed even before the child birth, as in other cases it is diagnosed shortly after birth through newborns screening testes.

In some cases the disorder is identified later during the adulthood, when the symptoms of inherited metabolism becomes apparent.

What are the tests done to diagnose inherited metabolic disorders?

The healthcare providers will diagnose the inherited metabolism with screening tests. However, screening tests include urine tests, blood tests, and physical exams. There are so many different types of inherited metabolic disorders, so the screening test for IM can include:

• Physical exam: Your healthcare provider may have a physical exam first, as they will talk about the symptoms you or your child is facing and the medical history. They may also ask you about your family history.
• Eye test: In some inherited metabolic disorders, the eye can also be affected, as it can affect a person’s vision. An eye exam will be done to check the person’s ability to see things clearly and to check the condition that affects the eyes.
• Metabolism test: In metabolism test, they take a look at fat, amino acid, protein and glucose metabolism patterns to help down the diagnosis. This test can be a blood test or a urine test.
• Blood glucose test: The healthcare provider will check your blood sugar(Glucose) level by taking a small sample of your blood. This test may be suggested to you if you have low energy, lethargy or seizures.
• Genetic test: Genetic test can identify any kind of inherited metabolism a person or the child has. Anyone in the family is diagnose with inherited metabolic disorder, specialists will suggest genetic counseling and testing for other family members too. The healthcare provider will take a swab of saliva inside your mouth or remove a small sample of your blood to examine the changes occur in the genes.
• Amniocentesis: In amniocentesis, the healthcare provider will take a small sample of amniotic fluid (the fluid that surrounds the fetus) to test it for genetic changes. 

Conclusion

Inherited metabolic disorders are mainly caused by the changes in specific genes that mostly affect a person’s metabolism. It can be genetic, or in some cases, it developed. There are hundreds of inherited metabolic disorders that can happen due to the changes in different genes. However, it can be diagnosed easily, and the treatment of inherited metabolic disorders can vary as there are so many types of inherited metabolic disorders. The good news is it is possible to reverse metabolism disorder with a change in lifestyle and medication.   

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