Autism is a developmental disorder which affects the growth and development of the brain and the central nervous system. It typically occurs in the first three years of life. It may also affect verbal communication, social interaction and may lead to restrictive and compulsive behaviour. It has been long believed that the main cause of autism lies in genetics.
Recent international studies show that about 1 in 68 people have autism. Through previous studies it has been established that boys are four times more likely to be diagnosed with autism than girls. Some have attributed this to the gender difference caused due to the X chromosome while others claim that females are better able to overcome genetic mutations. But a new study reveals something rather fascinating.
According to the findings presented at the Paediatric Academic Societies (PAS) annual meeting in San Diego, girls are diagnosed with autism spectrum disorder (ASD) later than boys because females exhibit less severe symptoms. Simply put, girls might hide their symptoms better which makes it difficult to diagnose the disease at an early stage. This indicates that girls face a higher risk of the disease not being recognised.
The study further noted that females also have different symptoms than males, possibly contributing to later identification of the disease. "This suggests that girls with ASD, as well as perhaps older women with this disorder, differ from males in key symptoms and behaviours, particularly around social interactions," said Paul Lipkin, director of the interactive autism network at Kennedy Krieger Institute in Maryland.
Researchers analysed data from an online registry that includes almost 50,000 individuals and family members affected by ASD. In the data review, researchers found that girls were diagnosed with pervasive developmental disorder, an ASD impacting the development of many basic skills, at a mean age of four years compared to 3.8 years for boys.
In addition, they found that girls struggled more with social cognition -- the ability to interpret social cues. Meanwhile, boys had more severe mannerisms such as repetitive behaviours like hand flapping, as well as highly restricted interests. Older boys, aged 10-15, also had more difficulties with the ability to recognize social cues and use language in social situations.
Researchers hope that these findings will help in diagnosing autism better. Further research needs to be conducted as less recognizable symptoms in girls may not only lead to later diagnosis, but also under-identification of the condition.