Different people with autism can have very different symptoms. Health care providers think of autism as a “spectrum” disorder (ASD), a group of disorders with similar features. One person may have mild symptoms, while another may have serious symptoms. But they both have an autism spectrum disorder. Now three new studies have been released that look even deeper into genetic abnormal variants that hope to eventually lead to better treatments of the many different types of autism.
It seems that the place where your brain transfers electricity between synapses and how your genes determine how these processes function are tied to autism in one way or another. There can be genetically driven disturbances in this process that lead to varying levels of autism.
Dr. Michael Wigler from Cold Spring Harbor Laboratory who led one of the studies comments:
“We observed a higher incidence of de novo (new) copy number variants in children with ASD than their unaffected siblings. The functions of the genes in the regions of de novo variation point to a great diversity of genetic causes, but also suggest functional convergence. In addition, our results show that, relative to males, females have a greater resistance to autism from genetic causes, which raises the question of the fate of female carriers.”
The authors compared DNA from affected and unaffected siblings using distinct versions of a sensitive and powerful genetic screening technique which, combined with the large sample size, allowed discovery of copy number variations (CNVs) on a finer scale than was previously possible.
At Columbia University in New York City, the CNVs identified in Dr. Wigler’s study were analyzed using a new method which revealed that the affected genes are part of a large network involved in the development of synapses, key sites of communication between neurons.
In another study still, Dr. Matthew W. State from Yale University also identified six rare recurrent de novo CNVs and found a significant association of ASD with de novo duplications of a chromosomal region that, when deleted, causes Williams-Beuren syndrome, a rare neurodevelopmental disorder which is associated with a highly social personality.
Williams syndrome (WS) is a genetic condition that is present at birth and can affect anyone. It is characterized by medical problems, including cardiovascular disease, developmental delays, and learning disabilities. These occur side by side with striking verbal abilities and an affinity for music.
WS affects 1 in 10,000 people worldwide with an estimated 20,000 to 30,000 people in the United States. It is known to occur equally in both males and females and in every culture.
Dr. State explains:
“Finding strong evidence that at one position in the genome increases in the genetic material lead to ASD, while losses at precisely the same region lead to a highly social personality, was particularly exciting. This relatively small genomic interval clearly holds important clues to understanding the social brain.”
State concludes with a comment regarding these groundbreaking studies collectively, and how these studies highlight the importance of diverse rare genetic variations in autism:
“These studies represent a significant step forward in understanding the genomic architecture of ASDs and provide important new points of traction in elaborating the molecular mechanisms and developmental neurobiology underlying ASDs. This type of knowledge is a critical first step in developing novel treatment approaches.”
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Written by Sy Kraft