Autism on the Increase

Nov. 28, 2014

By Medical Discovery News

Autism on the Increase

Based on statistics, you probably know someone with a form of autism. Autism rates in America grew by 30 percent from 2008-2010 and have doubled since 2000. Now, one in 68 eight-year-olds are diagnosed with autism. On average, one child in each grade of every elementary school has autism.

What is responsible for the remarkable rise of this disease? Perhaps we have gotten better at diagnosing it. Now, research is working to establish how autism occurs, even before birth, and how to diagnosis it sooner.

Autism is actually not a single disease but a spectrum of disorders. It is clearly related to infant development and is caused by differences in the brain. There are multiple causes of autism, but most are not yet known. One possible connection is that people tend to conceive later. The age at which women give birth has been increasing for many years and is linked to higher chances of autism.

Diagnosis of autism spectrum disorders (ASD) relies on observing differences in a person’s communication, social skills, and typical behavior. Roughly one-third of those with autism are also diagnosed with intellectual deficits, but the remaining two-third have normal or above average intelligence. Most are diagnosed at four years old but some are identified by age two. This is critical because research has repeatedly shown that the earlier therapy starts, the more likely it will result in substantial improvement.

A new study published in the “New England Journal of Medicine” suggests that ASD begins long before birth. This study documented changes in the cerebral cortex, which is the outermost layer of the brain. Almost 90 percent of children with autism had abnormal developments of their cerebral cortexes, centered in regions associated with social and emotional communication and language. These changes appeared as patches in the brain, suggesting that they occur during the child’s development in the womb. This may also explain why early interventions are more effective, as the brain is still developing. Currently, there is no way to spot these patches appearing on the cortex during gestation or in infants, but it could be an area of future research.

However, another study, reported in the journal “Nature,” suggests that eye-tracking technology can detect autism in two- to six-month-old children. This technology looks at the ability of babies to make eye contact with adults. Those with autism show a steady decline in eye contact starting at two to six months of age. This seemingly simple behavior is actually quite complex and difficult to quantitate, requiring sophisticated video technology. Such eye movements are not noticeable to parents. If larger studies prove successful, this may become a way to screen infants for autism and begin therapy as soon as possible.

Autism will continue to make headlines as a leading childhood health concern. As always, if you have concerns about your child’s activity, speech, or social interactions, talk with your pediatrician.

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Does Grey Matter?

Aug. 8, 2014

By Medical Discovery News

The brain

What do brain scientists and fans of E. L. James have in common? They are both passionate about shades of grey. Results from a recent study in the scientific journal “Molecular Psychiatry” indicate that grey matter really does, well, matter. This study shows that the thickness of grey matter in the brain may be linked to intelligence and may also explain why some people have learning difficulties.

Grey matter is the outermost region of the brain, a layer of tissue two to four millimeters thick covering the brain on both sides with a wrinkled surface. Underneath the grey matter, also called the cerebral cortex, is the white matter of the brain, the cerebrum.

Grey matter is responsible for some major human functions including awareness, attention, consciousness, language, thought, and memory. Previous studies have shown that animals with bigger brains generally have thicker cortexes, but there has not been a strict link between intelligence and the thickness of the grey matter until now. 

For this new study, researchers at King’s College London’s Institute of Psychiatry obtained brain scans and DNA samples from 1,583 14-year-olds. They also tested the verbal and nonverbal intelligence of these subjects. Using DNA analysis, scientists looked for gene variants that could be responsible for the intelligence differences of this group. This proved to be a daunting task as they discovered more than 50,000 gene variants associated with brain development. However, with the help of computation biology, researchers uncovered some astounding results. Those with one particular gene variant caused by a single nucleotide polymorphism (or change) had thinner grey matter on the left side of their brains. And, these same individuals tested lower on the intelligence tests. 

Called NPTN, this gene encodes a protein that works in brain cells called neurons. The variant of NPTN affects communication between neurons in the brain, thereby explaining its impact on important functions of grey matter. Additional experiments suggest the NPTN variant may have more of an effect in the left side of the brain than the right side. This may correlate to lower intelligence due to the function of this important gene and its encoded protein in the left brain. 

While important, NPTN is not the only thing that determines intelligence – a multitude of other genes and environmental influences are clearly involved as well. However, this gene may provide new clues as to how intelligence is built in humans. Also, it will be interesting to see if this gene variant is associated with cognitive diseases like autism or psychological disorders like schizophrenia. 

Thanks to the new B.R.A.I.N. initiative that funds basic and translational research, we look forward to better understanding the human brain, arguably one of the most important human organs we know the least about. 

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