Genetic knowledge may be beneficial related to issues such as selection of optimal supportive care, informed medical decision-making, prognostic considerations, and avoidance of unnecessary testing.

Genetics is the study of heredity or how different characteristics (traits) are passed from a parent to a child. A person inherits these traits from their parents. Each person has several thousand genes that are made up of DNA. Genes are packaged into larger structures called chromosomes. Chromosomes are present in almost every human body cell. Genetics play a part in many types of epilepsy.

Advances in science and technology can help identify molecular defects (for example, deletions or mutations) that contribute to the genetics of some types of epilepsy. Genetic testing helps scientists and physicians better understand how various genes may interact to produce a specific epilepsy syndrome. This genetic information may give people with epilepsy and their families more detail about their specific epilepsy syndrome. Several epilepsies have a genetic component and we know that epilepsy can run in families.

Usually, genetic testing requires a blood or salivasample to be taken from the person with epilepsy. The sample is then sent to a laboratory for genetic testing. The test looks at the DNA in the persons blood or saliva. The sample is analyzed for mutations or changes in a subset of genes that have a known association with different types of epilepsy.

There are five types of genetic disorders:

The inheritance of epilepsy is frequently complex. Genetic disorders can cause epilepsy alone or may cause a syndrome that affects various parts of the body as well as epilepsy. Some epilepsy syndromes are known to have a genetic basis, but the gene or genes that cause the syndrome have not yet been identified. Finally, some genetic disorders arise spontaneously through new gene mutations.

More than 20 different syndromes with epilepsy as a main feature have been mapped to specific genes. Many more single gene disorders that cause brain abnormalities or metabolic disorders have epilepsy as a primary symptom. Also, scientists have identified mutations in genes that control sodium, potassium, and calcium channels that can also cause epilepsy.

Its important to note that genetic testing in some epilepsy syndromes has already played a significant role in clinical practice. This has been particularly true for people with epileptic encephalopathies that begin in infancy and early childhood. For example, this may include:

More challenging at this time are the subgroup of genetic generalized epilepsies (GGE) that include childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, photosensitive epilepsy, and generalized tonic-clonic seizures. GGE has a complex genetic inheritance pattern. This subset of epilepsies present a challenge, and currently we have little information about the genes that are implicated in GGE.

However, genetic testing still may have a key role to play. Over time, as more information is collected, the cause of these epilepsies will be better understood. Knowing the cause may improve testing, diagnosis, clinical treatment, and family counseling.

Below are listed some of the epilepsy syndromes that may result from genetic disorders. New genes involved in epilepsy are being identified regularly, and the genetics of epilepsy spectrum continues in a period of rapid growth.

Single Gene Epilepsy Syndromes

Other Single Gene Disorders that Can Manifest as Epilepsy

Other Inherited Metabolic Conditions that May Cause Seizures

Multifactorial Disorders

Mitochondrial Disorders

Chromosomal Disorders

Visit link:
Genetic Testing | Epilepsy Foundation

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