How do SCN1A mutations cause epilepsy?

The SCN1A gene codes for a sodium channel protein that regulates brain cell activity. Changes in the DNA sequence of the gene (referred to as variants) alter the sodium channel protein and lead to the brain being more susceptible to seizures.

What chromosome is the SCN1A gene on?

The SCN1A gene is located on the chromosome 2q24, composed of 26 exons spanning 6030 bp and encodes the large α-subunit of the voltage-gated sodium ion channel, type 1 (NaV 1.1)28 (see Figure 1).

What mutation causes Dravet syndrome?

Around 80-90% of Dravet syndrome cases are caused by mutations in the SCN1A gene. Hundreds of mutations in this gene have been identified that are linked to seizures caused by high fever. The SCN1A gene provides instructions to build a protein that forms a subunit of a sodium channel called NaV1.

How many exons in SCN1A?

The SCN1A gene is located on chromosome 2 of humans, and is made up of 26 exons spanning a total length of 6030 nucleotide base pairs (bp). Alternative splicing of exon 5 gives rise to two alternate exons.

How long can you live with Dravet syndrome?

Dravet syndrome is a rare, severe, and lifelong form of epilepsy (seizure disorder). Most people affected by this condition have a good life expectancy. The disease typically starts in the first year of life, and around 80-85% of the children survive into adulthood.

What are the symptoms of Dravet syndrome?

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 is Doose Syndrome?

Myoclonic astatic epilepsy (MAE), also known as Doose syndrome, is an epilepsy syndrome of early childhood, most commonly appearing between ages 1 and 5 and featuring generalized seizures. Children will experience drop attacks and staring seizures, sometimes associated with falls.

Can you grow out of Dravet syndrome?

Does Dravet syndrome affect the immune system?

Dravet patients have an abnormal inflammatory reaction to vaccines, supporting a potential link between inflammation and epileptic seizures in these patients, according to a small study. The study, “Altered vaccine-induced immunity in children with Dravet syndrome,” was published in the journal Epilepsia.

Does Dravet syndrome get worse?

It is lifelong. It usually presents with a prolonged seizure with fever that affects one side of the body. Most cases are due to severe SCN1A gene mutations. Most children develop varying degrees of developmental disability.

Does Dravet syndrome go away?

Although there is no cure for Dravet syndrome, most treatments aim to reduce seizures. First line anti-seizure medications include clobazam (Onfi, Frisium) and valproic acid (Depakote, Depakene). Second line treatments include stiripentol (Diacomit), topiramate (Topamax), and the ketogenic diet.

What is sunflower syndrome?

Sunflower syndrome is a rare photosensitive epilepsy which has received little attention in recent medical literature. The historical cases documenting the epilepsy’s stereotyped handwaving motion in front of light characterized the behavior as self-inducing seizures via mimic of stroboscopic effect.