Caption: Child watches video while researchers track his eye movements. Credit: Washington University School of Medicine, St. Louis
From the time we are born, most of us humans closely watch the world around us, paying special attention to people’s faces and expressions. Now, for the first time, an NIH-funded team has shown that the ways in which children look at faces and many other things are strongly influenced by the genes they’ve inherited from their parents.
The findings come from experiments that tracked the eye movements of toddlers watching videos of other kids or adult caregivers. The experiments showed that identical twins—who share the same genes and the same home environment—spend almost precisely the same proportion of time looking at faces, even when watching different videos. And when identical twins watched the same video, they tended to look at the same thing at almost exactly the same time! In contrast, fraternal twins—who shared the same home environment, but, on average, shared just half of their genes—had patterns of eye movement that were far less similar.
Interestingly, the researchers also found that the visual behaviors most affected in children with autism spectrum disorder (ASD)—attention to another person’s eyes and mouth—were those that also appeared to be the most heavily influenced by genetics. The discovery makes an important connection between two well-known features of ASD: a strong hereditary component and poor eye contact with other people.
Research shows that the roots of autism spectrum disorder (ASD) generally start early—most likely in the womb. That’s one more reason, on top of a large number of epidemiological studies, why current claims about the role of vaccines in causing autism can’t be right. But how early is ASD detectable? It’s a critical question, since early intervention has been shown to help limit the effects of autism. The problem is there’s currently no reliable way to detect ASD until around 18–24 months, when the social deficits and repetitive behaviors associated with the condition begin to appear.
Several months ago, an NIH-funded team offered promising evidence that it may be possible to detect ASD in high-risk 1-year-olds by shifting attention from how kids act to how their brains have grown . Now, new evidence from that same team suggests that neurological signs of ASD might be detectable even earlier.
Caption: Mouse fibroblasts converted into induced neuronal cells, showing neuronal appendages (red), nuclei (blue) and the neural protein tau (yellow). Credit: Kristin Baldwin, Scripps Research Institute, La Jolla, CA
Writers have The Elements of Style, chemists have the periodic table, and biomedical researchers could soon have a comprehensive reference on how to make neurons in a dish. Kristin Baldwin of the Scripps Research Institute, La Jolla, CA, has received a 2016 NIH Director’s Pioneer Award to begin drafting an online resource that will provide other researchers the information they need to reprogram mature human skin cells reproducibly into a variety of neurons that closely resemble those found in the brain and nervous system.
These lab-grown neurons could be used to improve our understanding of basic human biology and to develop better models for studying Alzheimer’s disease, autism, and a wide range of other neurological conditions. Such questions have been extremely difficult to explore in mice and other animal models because they have shorter lifespans and different brain structures than humans.
For children with autism spectrum disorder (ASD), early diagnosis is critical to allow for possible interventions at a time when the brain is most amenable to change. But that’s been tough to implement for a simple reason: the symptoms of ASD, such as communication difficulties, social deficits, and repetitive behaviors, often do not show up until a child turns 2 or even 3 years old.
Now, an NIH-funded research team has news that may pave the way for earlier detection of ASD. The key is to shift the diagnostic focus from how kids act to how their brains grow. In their brain imaging study, the researchers found that, compared to other children, youngsters with ASD showed unusually rapid brain growth from infancy to age 2. In fact, the growth differences were already evident by their first birthdays, well before autistic behaviors typically emerge.
Credit: Centers for Disease Control and Prevention
I was born in 1950 and was home-schooled until the 6th grade. Thus, I missed exposure to several childhood illnesses that affected most of my generation. I never gave it much thought until, as a medical resident in North Carolina in 1979, I came down with a potentially life-threatening febrile illness that required hospitalization. Only after four days of 105 degree fever did a rash appear, and the diagnosis was made: measles. That was the sickest I have ever been. It turned out that one of my daughter’s school friends had developed measles in a small outbreak of unvaccinated kids in Chapel Hill, and I had been exposed to her. I was born too early to have been vaccinated.
But for most people born in the United States after the 1960s, they have never had to experience the high fever and rash of the measles or the coughing fits of pertussis, commonly known as whooping cough. That’s because these extremely contagious and potentially life-threatening diseases have been controlled with the use of highly effective vaccines and strong vaccination programs. And yet, the number of Americans sickened with measles and pertussis each year has recently crept back up.
Now, an NIH-funded report confirms that many of the recent outbreaks of these vaccine-preventable diseases have been fueled by refusal by some parents to have their children vaccinated . The findings, published recently in JAMA, come as an important reminder that successful eradication of infectious diseases depends not only on the availability of safe and effective vaccines, but also on effective communication about the vaccines and the diseases they prevent.