EARLY changes during brain development may hold the key to autism, say researchers.
The new finding follows claims by Donald Trump that paracetamol taken by pregnant women increases risk of the condition in some children.
Epigenetic changes in the brain have offered new insights into how conditions like autism arise[/caption]
US President Donald Trump has claimed paracetamol when taken in pregnancy causes autism[/caption]
The US President made the claim on Monday that taking Tylenol, known as paracetamol in other places, “is no good” and that pregnant women should “fight like hell” to only take it in cases of extreme fever.
Since then, medical experts have strongly pushed back, and health officials in the UK have stressed paracetamol remains the safest painkiller available to pregnant women.
Now, scientists at the University of Exeter have offered new insights into how conditions like autism arise.
They did so by mapping chemical changes to DNA during development and ageing of the brain.
The team specifically studied epigenetic changes – chemical tags on our DNA that control how genes are switched on or off.
These changes are crucial in regulating how information in genes is used, and guides brain cells to develop correctly.
An important mechanism, known as DNA methylation, was examined in nearly 1,000 donated human brains, from life at just six weeks after conception through to 108 years of age.
The researchers also focused on the cortex – the region of the brain involved in thought, memory, perception and behaviour – as correct development of the cortex during early life leads to healthy brain function after birth.
Published in Cell Genomics, the study findings revealed DNA methylation changes dramatically before birth, reflecting the activation of key biological pathways needed to build the cortex.
And genes linked to autism, as well as schizophrenia, were found to undergo specially dynamic DNA methylation changes during brain development.
This suggests genes play a vital role during development of the brain’s cortex, and disruptions to these processes could contribute to these conditions.
Alice Franklin, from the University of Exeter, who is first author on the study, said: “By analysing how chemical changes to DNA shape the brain across the human lifespan, we’ve uncovered important clues about why neurodevelopmental conditions like autism and schizophrenia may develop.
“Our findings highlight that their roots may lie very early on in brain development.”
Professor Jonathan Mill at the University of Exeter, who directed the research added: “This work gives us a clearer picture of the biological processes guiding brain development and how these differ across cell types.
“In the long term, this could help us move closer to understanding the mechanisms underpinning neurodevelopmental conditions.”
Previous evidence has suggested autism may be genetic, although scientists have been attempting to identify which genes might be implicated for some years.
According to the National Autistic Society, autism is likely to have multiple genes responsible rather than a single gene.
The UK charity also advises: “There is no link between autism and vaccines. Much research has been devoted to this issue over the years and the results have comprehensively shown there is no link.”
Key characteristics of autism
These are some features of autism that many people with it experience. Autism is a spectrum, so everyone shows symptoms differently.
Sensitive to senses
Autistic people can be much more or less sensitive than non-autistic people to the five main senses (sight, sound, touch, taste and smell).
This also extends to senses for balance, movement, spatial awareness and awareness of internal states, such as hunger and temperature.
Social differences
People with autism may find social interactions harder because they have difficulty; interpratiting social cues; facial expressions; maintaining eye contact; recognising sarcasm.
They may find tehy prefer to spend time alone because social interactions can be confusing.
Autism can be verbal (someone who uses communication) or non-verbal (they use other means to communicate). People can flit between the two.
Repetitive behaviours
‘Restricted and repetitive behaviours and interests’ is often listed as a trait of autism, but the National Autistic Society says many people with the condition actually find these behaviours as positive and helpful.
It is also sometimes referred to as stimming or self-regulatory behaviour.
Examples include having a strong passion or interest in a hobby, repeated behaviours like hair twirling or rocking, and preference for routine or rules to be followed.
Emotional dysregulation
People with autism may struggle to manage feelings such as frustration, anxiety, or sadness, which could lead to a ‘meltdown’ (extreme or intense outburst of emotions) or ‘shutdown’ (withdrawal).
Source: National Autistic Society
