Various Genetic and Rare Epilepsy Syndromes

What Is Meant by Epilepsy?

Epilepsy is a brain condition that is characterized by repeated episodes of seizures. This can be caused due to genetic conditions or some injury to the head, such as trauma or stroke. Involuntary movements characterize this condition, including part of the body or the whole body. At times the seizure episodes are accompanied by loss of consciousness and uncontrolled bowel and bladder functions. Seizure is caused due to sudden electrical activities in the brain cells, which can vary in frequency. The occurrence of one seizure will not signify epilepsy, but the occurrence of more than one episode of unprovoked seizure is called epilepsy.

What Are the Symptoms Associated With Epilepsy?

The signs and symptoms associated with epilepsy are based on the type of epilepsy that affects the person. Some common signs and symptoms are

• Temporary confusion.

• Staring spells.

• Stiffness of muscle.

• Uncontrolled jerking movements of limbs.

• Uncontrolled bladder functions.

• Loss of consciousness.

• Fever or anxiety.

What Is Meant by Rare Epilepsy?

Epilepsy is considered to be the fourth most common neurological condition that is diagnosed among 65 million people worldwide. Similar to cancer, epilepsy does not compress a single condition. Instead, it is a combination of various causes. The leading causes of epilepsy are:

• Genetic.

• Structural.

• Metabolic.

• Immune-related.

• Infection.

Epilepsy is not a rare condition, but various causes of epilepsy can be rare. When the underlying cause of this condition affects people less than 2,00,000, it is called rare epilepsy. Some of the rare epilepsies are:

• SLC13A5 (Solute carrier antibody 13).

• Dup15q (Duplication syndrome).

• Angelman (genetic disorder with developmental delay).

• Dravet syndrome (rare type of epilepsy).

• CDKL5 (Cyclin dependent kinase 5).

What Are the Types of Seizures Associated With Rare Epilepsy?

Various types of seizures are associated with rare epilepsy. These types can change over time and vary greatly based on the frequency and severity. Most people diagnosed with this condition will not respond to anti-epileptic drugs.

How Is Rare Epilepsy Diagnosed?

The diagnosis of rare epilepsy is challenging. Most of these conditions are either missed or misdiagnosed. It is usually misdiagnosed as a seizure, where the anti-epileptic drug the doctor recommends does not help. However, certain tests help diagnose this condition early in life; some tests are

• Genetic Testing:

Genetic testing is a medical test that shows any alteration in the gene, chromosome, or protein.

• EEGs:

Electroencephalogram is the monitoring of the brain’s activity.

Even with these advanced diagnostic methods, 50 % of people diagnosed with rare epilepsy will not know the underlying cause.

How Is Rare Epilepsy Managed?

Most seizures are treated using anti-epileptic drugs, but these medications do not work in rare epilepsies. Alternative treatment methods for this condition include changes in diet, surgery, and devices. In the case of rare epilepsies, new precision therapies are used, where the person’s genetic information is used to customize treatment for the patient.

What Is Meant by Genetic Epilepsy?

Genetic mutation can be an underlying cause of epilepsy. These mutations can be inherited from the parents or a new genetic mutation. Genetic changes are the underlying reason for about 75 % of epilepsies. Most people whose parents are affected by epilepsy have a higher chance of inheriting it other than those whose parents are not affected. This can occur when the person inherits an altered gene from the parent. Some epilepsies caused due to genetic conditions are

• Tuberous sclerosis.

• Fragile X syndrome.

• Rett syndrome.

• Neurofibromatosis 1.

How to Find Out Whether Epilepsy Is Due to Genetic Causes?

There are various signs and symptoms by which genetic epilepsy can be diagnosed. People have a higher chance of getting genetic epilepsy if

• The person has a family history of genetic epilepsy.

• The person shows signs and symptoms of epilepsy in early life with normal results of blood tests and MRI ( magnetic resonance imaging) scans.

Which Genes Are Responsible for the Occurrence of Epilepsy?

Researches show that about 84 genes are known to cause epilepsy or may cause signs and symptoms of epilepsy. In addition, almost 73 genes are associated with malformation in brain development. Some of the disorders related to the CNS (central nervous system) can also result in epilepsies.

What Is Meant by Genetic Testing?

Genetic testing is one of the diagnostic methods to rule out genetic epilepsy. This procedure involves testing the gene to see for any alterations in the gene that could result in epilepsy. This test is performed by taking samples of saliva or skin biopsy. Genetic testing is performed for the following reasons:

• To rule out the cause of epilepsy.

• This procedure helps to find the exact cause of the condition.

• This helps to find out the best form of treatment or medications to be used.

• This gives detailed information regarding the outcome of the condition in the long term.

• This also helps parents to know whether there are chances of giving birth to their child with epilepsy.

What Are the Results Obtained Through Genetic Testing?

• Positive Results:

Positive results show the presence of genetic epilepsy in people affected by epilepsy. A positive result in people without epilepsy shows the person is at greater risk of genetic epilepsy.

• Negative Result:

A negative result in people with epilepsy shows no gene changes, and further testing needs to be done to find the underlying cause.

• Uncertain Result:

This shows a change in the gene, but it is unclear what the alteration signifies.

What Are the Reasons That Can Cause Genetic Epilepsy?

There are some reasons for the occurrence of genetic epilepsy; these are

• Inheritance of a mutated gene from one or both parents results in genetic epilepsy.

• A new gene alteration in a newborn child can result in this condition.

• An alteration in the brain structure may be caused due to brain injury, stroke, brain tumor, or meningitis.

• Some genetic condition that is responsible for the alteration of the brain structure like tuberous sclerosis.

Conclusion

The occurrence of epilepsy is known to have a genetic cause if it is inherited from the affected parents or due to a new gene mutation. Some genetic epilepsies are even caused due to environmental factors. This condition is usually diagnosed with the help of genetic testing. Rare underlying conditions bring on rare epileptic seizures. In most cases, the diagnosis of this condition is challenging. Diagnosing the underlying cause and treating this condition helps to deal with rare epilepsy.