Researchers at Emory University School of Medicine have identified 5 rare mutations in genes on the X chromosome which increase the risk of autism spectrum disorder in boys.

X Chromosome

The mutations occur in a particular gene called AFF2 and is often associated with “Fragile X” syndrome. The mutations also occur in similar type genes in the X chromosome. This particularly affects boys because they only have one X chromosome. Girls have two X chromosomes so one can compensate for the other.

According to an Emory University press release, senior author Michael Zwick, PhD, assistant professor of human genetics at Emory University School of Medicine suggests, ”that AFF2 could be one of the major X-linked risk factors for ASD’s.” The key here being that it is “one of” the factors as genetic research has yet to find a single gene as a cause for ASD. In fact, it appears there are several genes that are susceptible to mutation and expressing themselves with autism type symptoms.

Little is known about the AFF2 gene, but research done in fruit flies suggest a similar gene is responsible for the creation of neurons. Zwick hopes to learn more about how this gene functions and how mutations affect it. They also hope to learn more about other X chromosome related mutations and how they might contribute to autism. This study was published in the journal Human Molecular Genetics.