[A child playing with lego blocks. Photo Credit to Unsplash]

A joint research team from Korea University, Seoul National University Bundang Hospital, the Synapse Brain Disease Research Unit of the Institute for Basic Science, and the University of Wisconsin-Madison has announced significant findings from the largest full-genome study of autism families in East Asia.

The research reveals genetic differences related to gender and has identified autism-related genes specific to males and females.

Autism is a neurodevelopmental disorder characterized by limited and repetitive patterns of behavior and challenges in communication and social interaction, experts say.

According to medical professionals, symptoms typically include difficulty in maintaining and initiating conversations, forming peer relationships, and a preoccupation with non-functional routines.

Historically, autism's prevalence has been about four times higher in males than in females, but the reasons behind this disparity have remained unclear.

Research shows that most gender-related autism studies have focused on European populations, with minimal studies involving East Asians.

While the complexity of autism includes a spectrum of clinical features, researchers note that the study of how these features manifest across genders is still in its early stages.

The research team's analysis of East Asian familial cohorts revealed 40 female-specific and 403 male-specific autism genes, suggesting different developmental mechanisms between genders.

Interestingly, while female-specific autism genes affected chromatin and histone, which are crucial for gene expression regulation, male-specific genes impacted synapses, which govern communication between nerve cells.

The researchers found that gender differences exist in the primary genetic causes of autism, such as de novo mutations and polygenic scores, which vary significantly with the severity of core autism symptoms and the presence of intellectual disabilities.

To conduct the study, comprehensive data on the clinical phenotypes of Korean families was collected to analyze the genetic makeup of parents and siblings.

The results showed that women, despite having higher polygenic scores suggesting a greater genetic predisposition to autism, tend to exhibit higher cognitive abilities and less severe autism symptoms than men.

Dr. Ahn, lead researcher of the study, emphasized that the rising diagnosis rates of autism globally underscore the importance of understanding the cellular and genetic relationships in autism.

The team’s findings build upon a recent study that highlighted somatic mutations in brain cells as a potential primary cause of autism, treating these mutations as analogous to cancer in the brain, offering a new perspective on the disease.

The researchers stress that further research is needed, especially regarding short tandem repeat (STR) variations in the human genome, which affect genes distributed across the frontal cortex from conception to birth.

These variations significantly impact the chromosome regulation and cognitive and social abilities of individuals with autism and their families.

Scientists explain that the STR, making up about 7% of the entire genome, influences external traits like eye color and height but also has implications in disorders like autism.

However, the randomness of STR variations, neither strictly hereditary nor environmental, underscores the complexity and the need for extensive research.

Previous studies in North America and Europe have primarily focused on single-nucleotide polymorphisms (SNPs), which account for the 0.1% of human genetic variation influencing aspects like skin color, appearance, and disease susceptibility, providing limited insight into the specifics of Korean populations.

This groundbreaking study not only broadens the understanding of autism's genetic underpinnings but also challenges the traditional research paradigms by highlighting the distinct genetic profiles and implications in East Asian populations, paving the way for new avenues for tailored interventions and therapies.