Scientists at Trinity College Dublin have made progress in identifying genes linked to autism, ADHD and epilepsy, as well as schizophrenia and other neurodevelopmental conditions.
Around the world, geneticists are working to understand which genes play a part in health conditions and in neurodevelopmental differences, and how those genes came to be.
In this study, Professor Aoife McLysaght and Dr Alan Rice drew up a shortlist of genes that may be involved in neurodevelopmental conditions, by looking at how those genes have changed over the course of human evolution.
Their findings were published in Nature Communications. The study looked at genes in connection with several conditions, including schizophrenia, ASD, ADHD, epilepsy, intellectual disability and developmental delay.
What Are Copy Number Variants?
Most of us have two copies of each gene, one from each parent. But some stretches of DNA can be duplicated or deleted, so a person has more or fewer copies of the genes in that stretch. These are called “copy number variants” (CNVs). They are common, and most are harmless.
Over the course of evolution, some genes have been duplicated or lost many times, while others have stayed remarkably stable. The researchers suggested that the stable genes are “dosage sensitive”: the body needs exactly the right number of copies.
“Our idea was that there must be some genes within these regions with ‘Goldilocks’ properties: too much or too little duplication, and things don’t work properly. The number of copies must be just right,” said McLysaght.
Scientists already know that some CNVs are linked to particular conditions, but it is not fully understood why some CNVs matter and others don’t. McLysaght and Rice say their work is a step towards a clearer picture.
Must Read : Autism and Epilepsy: Is There a Connection?
Genes Linked to Autism, ADHD and Epilepsy: What the Researchers Found
The team found that CNVs linked to these conditions were more likely to include dosage-sensitive genes, compared with CNVs that were not linked to any condition. Many of these genes are involved in early development.
“Our work demonstrates that our evolutionary history is useful for understanding human disease,” said McLysaght.
“These metrics also allow us to home in on a short list of genes as candidates for the diseases in question – some of which are seriously debilitating,” added McLysaght.
“Isolating specific genes that are linked to these disorders will increase our understanding of how and why they develop, lead to better diagnostics, and potentially help to develop therapies further down the line.”
McLysaght, a geneticist at Trinity College Dublin, is also well known for her work in science communication, and was featured in Silicon Republic’s Women Invent series in 2014.
Are Autism, ADHD and Epilepsy Linked?
Yes, they often occur together. Epilepsy is more common in autistic people than in the general population, especially when there is also an intellectual disability, and ADHD is common in both autistic people and people with epilepsy. Shared genes, including some of the dosage-sensitive genes in this study, are one reason. If your autistic child has staring spells, unusual movements or loses skills, talk to your doctor.
What This Means for Families
Research like this helps explain why autism, ADHD, epilepsy and other neurodevelopmental conditions often run in families and often occur together. A few things are worth knowing:
- Genes are only part of the picture. Autism is strongly genetic, but it usually involves many genes working together, not one single “autism gene”.
- Nothing you did caused it. Autism and ADHD are not caused by parenting, and research on genetics helps make that clear.
- Genetic testing may be offered. Some children, especially those with epilepsy, intellectual disability or developmental delay, may be referred for genetic testing such as a microarray, which looks for CNVs. Ask your pediatrician whether it would be useful for your child.
- Support doesn’t depend on a gene result. Whatever the cause, your child’s support should be based on their individual strengths and needs.
Understanding the genetics of neurodevelopmental conditions can lead to better diagnosis and support over time, and it reminds us that autism is a natural part of human variation.
I am Ash and I celebrate Neurodiversity! Growing up with an elder brother with severe Autism was tough – but it has also taught me essential life lessons. I don’t believe that people with Autism are necessarily or have any disorder (except in extreme cases). They are just different! And that is something to be proud of! I am passionate about helping other families who may have Autism conditions in their family. So please reach out and drop me a note. I will be glad to help 🙂
