What type of mutation causes Dravet syndrome?
In at least 80 percent of cases, Dravet syndrome is caused by defects in a gene required for the proper function of brain cells. Mutations in the SCN1A gene (a gene that encodes as a sodium channel, a part of the cell membrane involved in nervous system function) are the primary causes of Dravet syndrome.
What type of gene is SCN1A?
What is SCN1A? SCN1A (sodium voltage-gated channel alpha subunit 1) is a gene that provides instructions for making one part of a sodium channel called NaV1. 1. These channels control the flow of sodium into cells in the brain (neurons), which is necessary for electrical balance.
What is the life expectancy of a person 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.
Does Dravet syndrome cause brain damage?
Dravet syndrome is a disease characterized by prolonged and frequent seizures that begin in the first year of life and are difficult to control with medication. These seizures are harmful to the developing brain and can cause cognitive and behavioral impairment in patients.
Can you outgrow Dravet syndrome?
Children with Dravet syndrome do not outgrow their condition and the care required can severely impact quality of life for the individual and their family.
How is Dravet syndrome inherited?
Most cases of Dravet syndrome occur when the SCN1A gene is not working correctly. It can be inherited in an autosomal dominant pattern, but most people with Dravet syndrome do not have a family history of the condition. Diagnosis is based on a clinical exam, medical history, and the results of genetic testing.
Where is the SCN1A gene located?
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).
Is there a cure for Dravet syndrome?
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.
Is Dravet syndrome terminal?
About 15% to 20% of people with Dravet syndrome die before adulthood. Up to 20% of individuals with Dravet syndrome usually die from sudden unexpected death in epilepsy (SUDEP), long-lasting seizures and seizure-related accidents and injuries such as drowning and infections.
Is Dravet syndrome progressive?
Dravet syndrome is a severe and progressive genetic epilepsy characterized by frequent, prolonged and refractory seizures that usually begin within the first year of life.
Can people with Dravet syndrome talk?
Children with Dravet syndrome may be slow in learning to speak; they may also show signs of aphasia (difficulty in comprehending or producing speech) or agnosia (inability to interpret sensory information, such as speech).
Is Dravet syndrome rare?
Dravet syndrome affects an estimated 1:15,700 individuals in the U.S., or 0.0064% of the population (Wu 2015). Approximately 80-90% of those, or 1:20,900 individuals, have both an SCN1A mutation and a clinical diagnosis of DS. This represents an estimated 0.17% of all epilepsies.
What does SCN1A code for?
The SCN1A gene codes for the α-subunit of the neuronal voltage-gated sodium ion channel, type1 (NaV 1.1),2 and is expressed in the central and peripheral nervous systems and in cardiac myocytes.
Is Dravet syndrome a disability?
Dravet Syndrome is now one of the conditions that may qualify an individual for Social Security Disability claim processing under the SSA’s Compassionate Allowances guidelines.