Discovered: An Amino-Acid Deficiency That Causes Neurological Problems

By Ashley P. Taylor | September 11, 2012 8:21 am

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Our bodies are picky eaters when it comes to amino acids, and sometimes just a small screw-up can cause larger problems down the road. Scientists recently found an association between an amino-acid depleting mutation, and neurological problems in a small sample of humans. In mice with the same mutation, nutritional supplements reversed similar symptoms, offering the possibility of a treatment for the human disorder in the future. The results appeared in the journal ScienceThe study came about as part of a collaboration between Yale, University of California San Diego, and the Broad Institute to investigate the genetics of autism and epilepsy. The researchers started by sequencing the coding regions of six patients with autism, intellectual disabilities and, in three cases, seizures. They found mutations in a gene that produces an enzyme called BCKD-kinase, which is involved in a cascade of signals that lead to the degradation of certain amino acids.

The mutated enzyme in all of these patients normally inactivates another enzyme which, in turn, breaks down branched-chain amino acids. When BCKD-kinase is mutated this way, the second enzyme goes into overdrive and breaks down the amino acids from food prematurely, before the body can use them. To investigate this mutation, the researchers tested mice in which both copies of BCKD-kinase were inactivated. These mice had tremors and epileptic seizures that went away when researchers supplemented their diets with the missing amino acids.

Could amino-acid supplements help people with this mutation? Researchers are hoping to find out by conducting a clinical trial, the study’s head, Joseph Gleeson, from University of California, San Diego, told Ewen Callaway of Nature News. It’s unknown how many people have the mutation and therefore how many people could actually be helped by a treatment to compensate for the mutation, but it’s an interesting finding nevertheless.

CATEGORIZED UNDER: Health & Medicine, Mind & Brain
  • j.michael carney

    Could all these problems be human created? Vaccines , GMOs , Pesticides , Bioengineered products we know little about the long term effects of any of these new improved changes. Are we the answer to our own destruction? The Grey Goo Comith! I commented on a medical blogg a few years ago , I had read the autism rate in male babies was 1 in 88 , At that rate we would all be dragging each other around by the drool comming out of our mouths. I really think the scientists are doing a much better job than any terrosist group. I’ll give them just another few years and the whole planet will be a void of death. When Dr Don Huber came out with the danges of GMOs and round-up ,I thought more scientists would come out in favor of studing GMOs etc. but in the usa its all about the $. Money rules all test results ,the government,universities,corperations,and multibillion dollar families see to it that its there way or the highway.

  • Pippa

    re#1 – How on earth could vaccines, GMOs etc cause these genetic changes in people?

    My son is autistic and pulling straight A’s at university studying math and physics. Not a glob of drool in sight, or required for diagnosis.

    Do they still teach basic science in school?

    Or, was your comment maybe supposed to be funny?

  • Jake

    #1 I have never seen any study or data suggesting that GMOs are in any way harmful to the health of humans when consumed. As a chemist, my understanding of chemical biology is certainly not prolific, but it seems to go against logic that a slightly modified protein would make a significant difference in the way it is chewed up by proteases in your digestive system (barring that the protein is not pharmocologically active in another way)

    I am all for sustainable agriculture, getting away from monocultures, applying less chemicals, eating signficantly less meat products (especially beef), etc. because of the societal benefits that appear pretty plain to me. I do not, however, think that inventing evidence to indict GMOs helps that cause in the least bit.

    The anti-science push from the left is probably more offensive to me than that from the right. Right-wing activists are wrong to deny climate change, but at least they acknowledge that science and chemistry have changed what it means to be human for the better. The organo-crazy environmentalists are really convinced that any “chemicals” are “bad” and that chemistry does not improve our lives every single day. The link below demonstrates that militant environmentalism has severely damaged public understanding of chemistry.

  • Cody

    Very well spoken Jake, I strongly agree with you—it’s reassuring to see a sensible position. I don’t quite agree with the left/right characterization, as your link points out I think it is more the marketing that has distorted the meaning of the words “chemical” and “organic”, though I guess I’d agree it tends to be uninformed progressives/liberals rather than conservatives that buy into such distortions. I do agree it is a big problem, on the order of climate change and evolution denial (which I consider to be primarily conservative-backed).

    j.michael carney, more scientifically-tenable hypotheses might include:
    1. that we are more keenly aware of the details of human behavior and thus more capable of detecting subtle problems;
    2. we have technology & techniques more capable of measuring and revealing subtle problems;
    3. we have alleviated virtually every major concern to our health (predators, weather, disease), leaving us more time to obsess over the less significant threats;
    4. we have lowered the rate of infant mortality to the point where nearly every child survives to maturity, thus altering the gene pool in a significant way;
    5. we have radically different stressors than our ancestors (the cubical is a recent invention);
    6. we have a poor understanding of the historical prevalence of these disorders (comparing apples to nothing);
    7. over-diagnosis (in the case of mental illness, which are notoriously difficult to define and diagnose).

    I’m no expert on this stuff so some well informed people might be able to rule out some or all of these hypotheses, but they were just off-the-cuff suggestions anyway.

    In the end you must remember that there is nothing about evolution by natural selection (or even artificial selection as we currently practice it) that would shape humans into disease-free, naturally happy creatures. On the contrary, the process of evolution will carry every existent genetic flaw from generation to generation so long as those flaws do not interfere with reproduction and survival until reproduction.

    Just a hundred years ago the overwhelming majority of our ancestors spent most of their day—indeed their entire lives—farming. Today we’ve streamlined and automated farming to a point where less than 2% of our population participates, and the rest of us have had to find new things to do. I suspect that in many ways we are still learning how to be happy with the increased free time, and that also we now have the leisure time to notice the many flaws we were too busy plowing to notice previously.

  • http://Discovery Su

    Quite right; the autism incidence is not higher; we diagnose more people and label them autistic erroneously. Some kids are just mentally handicapped, many of these will display autistic mannerisns, but it is a function of IQ and conditioning.

    5o years ago parents worked hard NOT to have their children labeled; there was no profit motive then (no SSI or medicaid advantage) these children, while somewhat odd, learned as well or better than average and went on to lead productive complete lives. These kids learned to relieve tensions in socially acceptable ways or sublimate their distress in art, music, numbers or obscessions with a goal.

    Another good point someone brought up, was as we move to increasingly more complex social situations, more people are incapable of fitting in apropriately: on a farm a Down Syndrome or Autistic kid might be an asset, they will bail hay or help feed animals, etc. and feel useful. In a 21st century society there are fewer of these jobs and the ones that do exist parents refuse to allow their children to train for or take–they don’t want their children to have to work for the same money they get “FREE” from SSI. We must stop infanilizing these kids let them bloom (see the above described kid doing well in college–he’ll do well in life and have a fully self-actualizing life at that) and take a place in society.

    Now we rob these children of productive lives by nurturing their disabilities until the kids become truly disabled. The same number of “true” children with autism remains what it was when Kanner identified it: A collection or constellation of stereotypical behaviors that children of AVERAGE or ABOVE AVERAGE IQ display but do not seem to be able to control; it is an Emotional Disorder.–About 1 in nearly 300 live births.

  • Oliver

    Are not amino acids created solely by the human body? So too with proteins – which are only made by RNA/DNA dynamics. The “proteins” in our foods are no longer bioactive entities to begin with.
    How does an amino acid in one’s food supposed to interact with the body processes? Have we actually ever seen this dynamic taking place? – In Vivo.


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