An abnormality in one's sex chromosome in the form of an extra Y chromosome has been related with a doubled risk of having autism, providing a new perspective on the higher prevalence of autism among males. Researchers suggest that the Y chromosome may hold significant implications for identifying autism risk factors.
Sex chromosomes play a crucial role in determining biological sex of an individual, with men typically possessing an XY configuration and women an XX configuration. However there are some individuals who exhibit abnormalities, such as having XXY or XYY configurations, a genetic condition known as sex chromosome aneuploidy. Autism, characterized by repetitive behaviors and social skills deficits, is known to be nearly four times more prevalent in men than in women, indicating a strong gender-related factor in its occurrence.
A team of researchers from the Autism and Developmental Medicine Institute in the US examined autism diagnoses among individuals with abnormal sex chromosomes. They discovered that those with an extra Y chromosome (XYY or XXY) had twice the likelihood of being diagnosed with autism compared to those with a typical chromosome structure. In contrast, an extra X chromosome did not correlate with increased autism risk. The analysis included genetic and autism diagnosis data from 177,416 patients, with 350 exhibiting abnormal sex chromosomes. Notably, the presence of XYY chromosomes was linked to a higher autism risk than that of XXY chromosomes.
Published in Nature Communications, the study highlights a potential risk factor associated with the Y chromosome, diverging from the protective effect attributed to the X chromosome. The established "female protective effect" suggests that women, who possess two X chromosomes, may have a reduced risk of autism due to the protective qualities of the X chromosome.
The authors emphasize the critical importance of exploring autism risk factors related to the Y chromosome, rather than solely focusing on the protective aspects of the X chromosome. They advocate for further research to pinpoint specific autism-related risk factors consistently associated with the Y chromosome.
Participants in the study were drawn from the Simons Foundation Powering Autism Research (SPARK) initiative and the MyCode Community Health Initiative, both located in the United States. This important research underscores the need for a broader understanding of genetic factors in autism development, particularly those specifically associated with male-specific chromosomes.
(This article is a reworked version of a PTI feed)
