Research by the University of California San Francisco
A large team of researchers from various universities recently completed a study at the University of California San Francisco that examined the relationship between white matter in the brain and autism. The lead authors of the study, Elliott Sherr and Park Mukherjee, ultimately concluded that genetic testing can be an increasingly reliable source of diagnosing autism, as evidenced through the results of their study.
Sherr and Mukherjee’s research focused specifically on the chromosomal region called 16p11.2, which is in the region on chromosome 16. They noted that the deletion or duplication of about 600 different characters in this chromosomal region can be a prime indication of whether or not an individual has autism.
Based on their research, the team determined that deletions of some of the 600 characters will typically lead to an increase in white matter in the brain. Conversely, duplication of any of the 600 characters will result in a reduced amount of white matter in the brain. A child affected by a genetic mutation at 16p11.2 will present different symptoms depending on whether there was a deletion or duplication.
The research team found that in children with a deletion, there tended to be more impediments to skills needed for daily living, social skills, and communication skills. This is likely because a deletion in the 16 region results in more white matter which affects the corpus callosum which is responsible for communication between the two sides of the brain.
Alternatively, the research team found that individuals with a duplication in the 16-region had a decreased amount of white matter which resulted in a smaller corpus callosum overall. This decreased white matter tended to result in an overall lower IQ in individuals, and especially a lower verbal IQ.
While the effects of a duplication or deletion are different with regard to how they change the development of the brain and how they present in individuals, the researchers were able to verify that a mutation in at 16p11.2 relative to npeople without autism is strongly related to the presence of autism.