Is Dravet syndrome a form of epilepsy?
Dravet syndrome (DS) is a severe form of epilepsy characterized by frequent, prolonged seizures often triggered by high body temperature (hyperthermia), developmental delay, speech impairment, ataxia, hypotonia, sleep disturbances, and other health problems.
What causes PCDH19 Epilepsy?
PCDH19 Epilepsy is a rare epilepsy syndrome with early onset seizures, cognitive and sensory delays, and behavioral problems. It is caused by a change or mutation of the PCDH19 gene found on the X chromosome. The PCDH19 gene makes a protein (called protocadherin 19) which helps cells in the brain communicate.
What kind of seizures are in Dravet syndrome?
The first seizure often happens with a fever and may be a tonic-clonic seizure or a seizure involving clonic (jerking) movements on one side of the body. Myoclonic seizures (brief shock-like jerks of a muscle or group of muscles) starting between 1 and 5 years in 85% of children with Dravet syndrome.
How does SCN1A cause epilepsy?
Interneurons normally suppress brain cells from generating electrical activity, but in the presence of the SCN1A variant, they are no longer able to adequately suppress electrical activity, leading to a predisposition to seizures.
What is the rarest type of epilepsy?
Dravet syndrome is a rare, catastrophic, lifelong form of epilepsy that begins in the first year of life with frequent and/or prolonged seizures. Previously known as Severe Myoclonic Epilepsy of Infancy (SMEI) 80% of people have a mutation in their SCN1A gene.
How does Dravet syndrome affect the brain?
Children with Dravet syndrome typically experience poor development of language and motor skills, hyperactivity, and difficulty relating to others. In 30 to 80 percent of cases, Dravet syndrome is caused by defects in a gene required for the proper function of brain cells.
How common is PCDH19 epilepsy?
About 1 in 10 girls that begin having seizures before the age of 5 may have PCDH19 Epilepsy. The features of PCDH19 can overlap or look similar to the features in Dravet Syndrome. It is estimated that there are between 15,000 and 30,000 people with PCDH19 Epilepsy in the United States.
What causes KCNQ2?
KCNQ2 is caused by a mutation on the KCNQ2 gene, located on chromosome 20. Chromosomes: Chromosomes are located in the nucleus of human cells and carry the genetic information for each individual. Human body cells normally have 46 chromosomes in each cell.
What is the life expectancy of someone with Dravet syndrome?
The average life expectancy of people with Dravet syndrome is not clear, but estimates suggest that 10–20% of individuals with Dravet syndrome do not survive beyond the age of 10. Sudden unexpected death in epilepsy (SUDEP) is the most common cause.
What does the SCN1A gene do?
The SCN1A gene belongs to a family of genes that provide instructions for making sodium channels. These channels, which transport positively charged sodium atoms (sodium ions) into cells, play a key role in a cell’s ability to generate and transmit electrical signals.
Is Dravet syndrome fatal?
Is Dravet syndrome life limiting?
Lifespan. An estimated 10-20 percent of Dravet syndrome patients pass away before reaching adulthood.