Gene linked to low IQ

March 25, 2014
Gene linked to low IQ

(Medical Xpress)—Children with both a common gene variant and lower thyroid hormone levels, which occurs in approximately 4% of the population, are four times more likely to have a low IQ, according to research presented today by the University at the Society for Endocrinology annual BES conference.

It is well established that thyroid hormones are essential for brain development in childhood. More recently, scientists have looked at a certain enzyme, called deiodonase-2, involved in processing thyroid hormones inside cells. A variant in the gene coding this enzyme has already been associated with key health outcomes including diabetes and high blood pressure, although the precise mechanism remains unclear.

In this study, researchers from Cardiff and the University of Bristol examined the genetic data and thyroid function of 3,123 aged 7 who also had their IQ tested, as part of the Avon Longitudinal Study of Parents and Children (ALSPAC). The researchers found that children with thyroid hormone levels in the lower part of the normal population range who also possessed this genetic variant were four times more likely to have an IQ under 85.

This result stood true after taking into account various differences in environmental and socio-economic factors such as social class. Children with lower thyroid hormone levels alone did not have an increased risk of lower IQ, highlighting that without genetic analysis the population at risk could not be identified.

The study's results will need to be confirmed in other groups of children. "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," said lead researcher Dr Peter Taylor, from the School of Medicine. "Children with satisfactory thyroid 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 processing," he added.

Explore further: Antenatal thyroid screening fails to improve IQ in 3-year-olds

Related Stories

Antenatal thyroid screening fails to improve IQ in 3-year-olds

February 8, 2012
Children of mothers screened and treated for reduced thyroid function during pregnancy show no signs of improved IQ compared to women who receive no treatment, new research has uncovered.

Active thyroid may raise risk of depression in older individuals

February 20, 2014
When older individuals' thyroid glands are more active than average, it may be a risk factor for depression, according to new research accepted for publication in the Endocrine Society's Journal of Clinical Endocrinology ...

Low thyroid levels may signal heightened risk of death in hospitalized patients

October 30, 2013
Older individuals hospitalized with a serious condition may face a slimmer risk of surviving if their thyroid hormone levels are low, according to a recent study accepted for publication in The Endocrine Society's Journal ...

Thyroid problems linked to irregular heart rhythm

November 28, 2012
People with an overactive thyroid gland (hyperthyroidism) carry a greater risk of developing irregular heart rhythm (known as atrial fibrillation) than those with normal thyroid function, finds a study published on BMJ today.

Secondary thyroid cancer more deadly than primary malignancy in young individuals

February 24, 2014
A new analysis has found that adolescents and young adults who develop thyroid cancer as a secondary cancer have a significantly greater risk of dying than those with primary thyroid cancer. Published early online in Cancer, ...

Recommended for you

Gene variant activity is surprisingly variable between tissues

August 21, 2017
Every gene in almost every cell of the body is present in two variants called alleles—one from the mother, the other one from the father. In most cases, both alleles are active and transcribed by the cells into RNA. However, ...

Genome analysis with near-complete privacy possible, say researchers

August 17, 2017
It is now possible to scour complete human genomes for the presence of disease-associated genes without revealing any genetic information not directly associated with the inquiry, say Stanford University researchers.

Science Says: DNA test results may not change health habits

August 17, 2017
If you learned your DNA made you more susceptible to getting a disease, wouldn't you work to stay healthy?

Genetic variants found to play key role in human immune system

August 16, 2017
It is widely recognized that people respond differently to infections. This can partially be explained by genetics, shows a new study published today in Nature Communications by an international collaboration of researchers ...

Active non-coding DNA might help pinpoint genetic risk for psychiatric disorders

August 16, 2017
Northwestern Medicine scientists have demonstrated a new method of analyzing non-coding regions of DNA in neurons, which may help to pinpoint which genetic variants are most important to the development of schizophrenia and ...

Phenotype varies for presumed pathogenic variants in KCNB1

August 16, 2017
(HealthDay)—De novo KCNB1 missense and loss-of-function variants are associated with neurodevelopmental disorders, with or without seizures, according to a study published online Aug. 14 in JAMA Neurology.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

katesisco
not rated yet Mar 25, 2014
The common unstated thyroid condition may be responsible for the 50% of women who are said not to have underarm perspiration, the 50% of women said not to be orgasmic, the 50% of LD children who mature with the dysfunction still present, ad nauseum. Perhaps the complex interactions of the HPA axis is at the base of this malfunction.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.