Signs of autism in boys as study finds condition more likely to be inherited by males

Mother with arm around son sitting on sofa at home
A new study has found that males are more likely to inherit autism than females -Credit:Getty Images

New research has found that autism spectrum disorder (ADS) is more likely to be inherited by males than females. It also found heritability for autism varies between genders.

The study was conducted by the Karolinska Institutet in Stockholm and looked at ‘sex-specific heritability’ of autism. Researchers analysed data from non twin siblings and cousins in Sweden who were born between January 1985, and December 1998 - following up on the results up to the age of 19 years old.

Results were published in the online journal Psychiatry this month. The study looked at 1,047,649 individuals from 456,832 families.

Researchers found that 1.17 per cent of the entire sample received a diagnosis of ASD. This included 1.51 per cent of males and 0.80 per cent of females.

As a result, ASD heritability was estimated at 87.0 per cent and 75.7 per cent, for males and females, respectively, with the difference in heritability estimated at 11.3 per cent. There was no support seen for shared environmental contributions.

The authors, including Sven Sandin, PHD, from the Karolinska Institutet, wrote: “The skewed sex ratio in ASD may, partly, be explained by differences in genetic variance between sexes. This discovery opens up new avenues for further research aimed at gaining a deeper understanding of the prevalence of ASD."

There’s a varying degree of signs in autism for both young and older children, and they can present differently based on gender, meaning it may be harder to spot in girls. The National Autistic Society has more information about the signs of ASD in women and girls.

Signs of autism

The NHS has composed a list of the signs of autism in children. Australian organisation Austism SA has also provided a checklist for boys. However, it is important to know symptoms can present differently in each individual.

The two areas of ASD which are most likely to be seen in boys include social communication and social interaction, and repetitive or restricted behaviour, interests or activities

Signs for autism in young children include:

  • not responding to their name

  • avoiding eye contact

  • not smiling when you smile at them

  • getting very upset if they do not like a certain taste, smell or sound

  • repetitive movements, such as flapping their hands, flicking their fingers or rocking their body

  • not talking as much as other children

  • not doing as much pretend play

  • repeating the same phrases

For those looking to know about signs of autism in older children, these can include:

  • not seeming to understand what others are thinking or feeling

  • unusual speech, such as repeating phrases and talking ‘at’ others

  • liking a strict daily routine and getting very upset if it changes

  • having a very keen interest in certain subjects or activities

  • getting very upset if you ask them to do something

  • finding it hard to make friends or preferring to be on their own

  • taking things very literally – for example, they may not understand phrases like "break a leg"

  • finding it hard to say how they feel