Shocking discovery: New study finds extra Y chromosome in humans and it's not a good news for some men

A recent study has found that an extra Y chromosome may double the risk of autism, providing a new perspective on why autism is more common in men. Researchers suggest a closer examination of the Y chromosome could help identify risk factors for autism. Sex chromosomes determine biological sex, with men typically having XY chromosomes and women having XX chromosomes. However, some individuals may have an abnormal number of sex chromosomes, such as XXY or XYY, which are classified as 'sex chromosome aneuploidy', a PTI report stated.

Autism and Gender Disparities

Autism is a neurodevelopmental condition characterized by repetitive behaviors and challenges in social skills. Studies indicate that autism is nearly four times more prevalent in men than in women, highlighting a significant gender disparity.

Study Findings

The research team from the Autism and Developmental Medicine Institute in the U.S. examined autism diagnoses among individuals with abnormal sex chromosomes. They discovered that individuals with an extra Y chromosome (XYY or XXY) were twice as likely to be diagnosed with autism. In contrast, having an extra X chromosome did not affect autism risk. The analysis included data from 177,416 patients, of whom 350 had abnormal sex chromosomes. Notably, those with XYY chromosomes faced a greater increase in autism risk compared to those with XXY chromosomes.

Implications for Autism Research

Published in the journal Nature Communications, the study suggests that the Y chromosome may serve as a risk factor for autism, challenging the prevailing notion that only the X chromosome offers protective effects. This aligns with the theory known as the 'female protective effect,' which posits that the X chromosome reduces autism risk in women.

The study authors emphasized the importance of exploring autism risk factors linked to the Y chromosome, rather than solely focusing on the protective role of the X chromosome. They called for additional research to identify specific autism risk factors associated with the Y chromosome.

The participants in this study were recruited from the Simons Foundation Powering Autism Research (SPARK) study and the MyCode Community Health Initiative, both based in the United States.