Autosomal dominant partial epilepsy with auditory phenomena (Autosomal dominant partial epilepsy With auditory features - ADPEAF-) - Gen LGI1.
Autosomal dominant partial epilepsy with auditory phenomena (ADPEAF) is a rare form of epilepsy which occurs in families. This disturbance causes seizures that are often characterized by sound - related symptoms such as buzzing or hissing. Some people have more complex sounds during a seizure, such as specific voices or music, or changes in the volume of sounds. Some people with ADPEAF become unable to understand the language before losing consciousness during a seizure. This inability to understand speech is known as receptive aphasia. Less often, seizures can cause visual hallucinations, a disturbance in the sense of smell, a feeling of dizziness or vertigo, or other symptoms that affect the senses.
Usually seizures associated with ADPEAF begin in adolescence or young adulthood. They can be triggered by specific sounds, but in most cases seizures have recognized triggers. In most of those affected, seizures are rare and can be controlled with medication. Most people have simple partial seizures, which do not cause a loss of consciousness. It is believed that these episodes begin in the lateral temporal lobe. In some people, the seizure activity can spread from side to other brain regions temporal lobe. If seizure activity spreads to involve the whole brain, causing a loss of consciousness, muscle rigidity, and rhythmic jerking. Episodes that begin as partial seizures and spread throughout the brain are known as secondary generalized seizures.
This process is due to mutations in the gene LGI1, located on the long arm of chromosome 10 (10q24). This gene encodes a protein rich in leucine called glioma inactivated 1 (LGI1) or epitempina. This protein is found primarily in neurons, including lateral temporal lobe. The temporal lobe of the brain is involved in hearing, speech, memory and emotion. Although the exact function of the protein in the brain remains uncertain, it is likely to be involved in normal brain development. Epitempina is believed to play a role in the normal function of the potassium channels in neurons. These channels are embedded in the cell membrane, which takes place the transport of potassium ions. Potassium channels are critical for normal signaling in these neurons. The epitempina protein can also help regulate communication between neurons. Probably epitempina to a receptor protein ADAM22 is called link on the surface of neurons. Together, these proteins help control the release of neurotransmitters.
They have identified at least 22 LGI1 gene mutations in people with autosomal dominant partial epilepsy with auditory phenomena (ADPEAF). Some mutations change the amino acids in epitempina protein, which alters the protein structure. Other coding mutations lead to an abnormally short, nonfunctional version of the protein. It is likely that the altered protein can not be secreted, remaining within cells and can not perform their usual functions. Although mutations in the gene LGI1 epitempina interrupt function, it is not clear how the altered protein leads to seizure activity in the brain.
This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell LGI1 is sufficient to increase the risk of developing epilepsy. About two - thirds of people who inherit a mutation in this gene develop seizures. In most cases, an affected person has an affected parent and other relatives with the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with autosomal dominant partial epilepsy with auditory phenomena (ADPEAF), by complete PCR amplification of exons LGI1 gene, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).