Cardiff University researchers report on Monday that children with two copies of a common gene (Thr92Ala), together with low levels of thyroid hormone are four times more likely to have a low IQ. It was found that this combination occurs in 4% of the UK populace.
In the future genome sequencing will become so cheap that almost anyone will afford to have their children’s genes sequenced right from the womb. Various combinations of genes, chemicals and other environmental factors in the womb greatly influence how your child will grow up to be. Soon, in addition to other findings sure to follow in like with these from Cardiff, scientists will be able to better predict if children will be born with a disease, how strong or how intelligent they may become. All of these raise an important question: if we can make children smarter, should we? What about cognitively disabled children – would you choose therapy for your unborn child if a doctor told you it would have a sub-average IQ? Would you choose that your baby gets more chances to make it in life? These are extremely tough questions and, thankfully, most of us are far from being in such a delicate position. I mean, we’ve all seen Gattaca for Christ’s sake.
Steadily science seems to be heading towards this scenario, though. For instance, mothers that choose in vitro fertilization (IVF) have their embryos routinely checked and diagnosed for major diseases. It’s likely gene screening will also be part of the diagnosis process.
Back to the study at hand, the Cardiff researchers found that a common gene variation and lower thyroid hormone levels were four times more likely to have an IQ under 85. Below 70 is classified as intellectual disability but an IQ of 70 to 75 is similar to mild intellectual disability. The findings seem to be a step further in the direction of neonatal screening. The researchers claim that the children could be treated with standard thyroid tablets, which should help them normalize their levels and balance their cognition.
Thyroid hormones are essential for brain development in childhood and, recently, scientists have looked at a certain enzyme, called deiodonase-2, involved in processing thyroid hormones inside cells. A variant of the same gene was also previously linked with diabetes and high blood pressure. Children with lower thyroid hormone levels alone did not have an increased risk of lower IQ, only those that also additionally have the Thr92Ala gene variant were at increased risk.
So, what happens is that essentially there’s no way to make your kids super smart, not yet at least, but there apparently may be a way to help a potential intellectually challenged child to level up.
Lead researcher Dr Peter Taylor from Cardiff University said: “If other studies confirm our finding then there may be benefit in carrying out a genetic test for this gene variant in addition to the standard neonatal thyroid screening which would identify children most at risk of developing low IQ.
“Children with satisfactory thyroid hormone levels together with the genetic variant have normal IQ levels, which raises the possibility that children at risk could be treated with standard thyroid hormone tablets to compensate for impaired thyroid hormone processing.”
People with rated IQs between 75 and 90 are faced with significant disadvantages, according to statistics. Individuals with this lower level of intelligence are at significant risk of living in poverty (16%), being a chronic welfare dependent (17%) and are much more likely to drop out of school (35%) compared to individuals with average intelligence.
The findings were presented at a conference of the Society for Endocrinology in Liverpool on Monday.