Separate Mutations in a Gene Lead to Either Infantile Epilepsy or Autism

By Kurtis Chien-Young

According to a study from the University of California - San Francisco, separate mutations of a single gene have been found to cause either infantile epilepsy or autism spectrum disorders. The result corresponds with whether the mutation increases the protein’s functionality or inhibits it.

These findings are significant, as they indicate how even small alterations in the fetal brain can generate such vast functional differences. The gene in question is called SCN2A, and most probably works as a genetic driver of autism spectrum disorders. A study at Yale University screened 4,000 autistic children and their families and found that spontaneous, non-inherited mutations were linked to the development of autism spectrum disorders in more than twenty percent of the cases.

The SCN2A gene encodes NaV1.2, a sodium channel protein which enables electrical communication between neurons. It plays a crucial role during the early stages of brain development. A professor at the University of California - San Francisco observed various SCN2A mutations within children with autism spectrum disorders and found that the mutations stopped or slowed the flow of sodium within the NaV1.2 channels.

In contrast, mutations in patients with infantile seizures were found to stimulate neurons to more excitable states. The notable difference between the mutations responsible for infantile epilepsy and those responsible for autism spectrum disorders seems to be whether they encourage or inhibit neuron activity during the early stages of brain development.

More research invested into why these genetic mutations alter the brain may further reveal the susceptibility of the brain during early stages of development. Researchers also hope to find whether or not there is a correlation between the specific SCN2A mutation in a patient and the degree of autism expressed. Furthermore, strong collaboration is expected between the fields of genetics and neurophysiology in order to investigate these gene mutations.

 

University of California - San Francisco. "Autism researchers discover genetic 'Rosetta Stone': Opposing defects in a single neuronal protein lead either to epilepsy in infancy or to autism." ScienceDaily. ScienceDaily, 26 January 2017. <www.sciencedaily.com/releases/2017/01/170126083605.htm>.