Researchers publishing in the journal Nature Medicine have sequenced the genomes of families affected by autism, looking in each case at two affected siblings and their parents. They report a large degree of variation in the mutations found in siblings, which translated as different clinical outcomes.
Dr Judith Brown, Head of Autism Knowledge and Expertise at the National Autistic Society, said:
“This is a robust piece of research which adds to our knowledge about the substantial and complex role genetics play in autism. Although it is reported to be the largest whole-genome sequencing data set published to date, the sample size is relatively small and, as the authors acknowledge, further study is necessary if we’re to truly understand autism’s genetic makeup.
“The paper reports on an investigation of 85 sets of parents who have two children with autism. The authors found that 69.4% of siblings with autism did not share gene mutations commonly associated with autism. However, those that did share the same mutations exhibited similar characteristics of autism. The authors suggest that even if parents have more than one child with autism, it is necessary to analyse the whole-genome sequencing of each individual in order to provide accurate data.
“The findings suggest there is significant genetic diversity among people with autism. This reaffirms the importance of viewing each person with autism as an individual and identifying support appropriate to their needs, rather than approaching all people in the same way.
“We still do not know what causes autism but the authors have provided the research community with high quality data which adds to an expanding genome resource and will support further studies.”
Dr Simon Wallace, Research Director, Autistica, said:
“The researchers used a novel technique to provide a detailed and comprehensive picture of the genetic architecture of families who have two children with an autism diagnosis.
“As has become increasingly evident in the last ten years the genetic causes of autism are heterogenous and for the majority of cases they are hard to identify with confidence.
“We hear in this study that even for siblings who both have autism that their condition can be caused by different factors.
“The authors suggest that their detailed analysis could ultimately be used in clinical settings to inform diagnosis but this is a long way off and needs further testing and larger sample sizes to increase confidence in findings.”
‘Whole-genome sequencing of quartet families with autism spectrum disorder’ by Yuen et al. published in Nature Medicine on Monday 26th January.