Showing posts with label GAMT. Show all posts
Showing posts with label GAMT. Show all posts

Monday 11 November 2013

Creatine, the Sub-types of Autism is Affects, and the Missing $26 million

Poly Genetic Theory of Autism

Autism appears to be the result of the expression of multiple abnormal genes acting in concert, likely initiated by some external factor(s).  This would explain why there are so many variants of autism and why there can seem to be autistic-like traits in close relatives.


Gene-based Autism Research
Several candidate genes have been identified, such as those linked to fragile X syndrome, tuberous sclerosis etc.  Researchers then follow the science from the target gene to identify a possible therapy.  At this point the researchers then seem to lose their scientific logic; they then try and apply their new therapy to all kinds of autism, i.e. the ones without the “faulty gene”.

This really goes back to our current limited understanding of the brain, medicine is more art than science, and we should perhaps suspend logic and accept this trial and error approach as valid.  At least call it trial and error.

Creatine is an organic acid produced naturally in the body.  It helps to supply energy to all cells in the body. This is achieved by increasing the formation of adenosine triphosphate (ATP).

Creatine is not an essential nutrient, as it is manufactured in the human body from L-arginine, glycine and L-methionine.
Its main use as a supplement/drug is among people wanting to develop their muscles, like athletes and bodybuilders.  Taking the standard dose of 5-10 mg has the same effect as eating a very high protein diet.  In people with muscle wasting diseases, Creatine is also used.  What I found interesting was the research showing an effect in depression.  There are marked similarities between conditions like depression and ASD.
We will return later in the post to another reason that Creatine may be relevant to autism; it appears to be something the research community did not notice.  Now back to those professional researchers:-
Creatine Deficiency
Science has identified three types of Creatine deficiency and all three lead to mental retardation and/or autism.  Two types are very rare, but are treatable; the third type is far more common, affecting about a million people worldwide, and is currently untreatable in humans.  In mice, this third type has been “cured”, but the money is not yet available to develop and test a human version of the therapy.
1.      AGAT 
AGAT (L-Arginine:glycine amidinotransferase) is an enzyme.  This enzyme is needed for the body to produce Creatine.  AGAT deficiency will cause Creatine deficiency  and lead to mental retardation and autism.
For those regularly following my blog, please note the following: It has been suggested that AGAT activity in tissues is regulated in a number of ways including induction by growth hormone (GH) and thyroxine (T4).

The actual genetic mutation associated with AGAT involves a tryptophan codon being converted to a stop codon at residue 149.
You may recall in my post on serotonin, we learnt about its precursor tryptophan and how it appears to be degraded in the autistic brain.

2.     GAMT
GAMT (Guanidinoacetate N-methyltransferase) is another enzyme required to produce Creatine.  As with AGAT deficiency, if you are deficient in GAMT, autism and mental retardation will follow.

If diagnosed, defects of Creatine biosynthesis are treated with Creatine supplements and, in GAMT deficiency, with ornithine and dietary restriction of arginine through limitation of protein intake.
3.     X-linked Creatine deficiency
The final type of Creatine deficiency is much more common, but is much more difficult to treat.  The defect is the Creatine transporter that should allow the Creatine into brain cells, where it plays a critical role in the brain’s energy needs.  No matter how much Creatine you give to people with this disorder, they cannot use it, because their Creatine transporters (CRTs) are defective.

Fortunately, thanks to Dr Joseph Clark, Professor of Neurology at the University of Cincinnati, there is light at the end of the tunnel.  Dr Clark has been researching the Creatine metabolism for some years.  Very unusually, he has been sharing his experiences with us, via his blog.
To cut a long story short, the good doctor has figured out that by using an analog (a modified version) of Creatine called cyclocreatine he could normalize the function of mice with  X-linked Creatine deficiency.  All he now has to do, is to make it work in humans, fully test it and get it FDA approved.  The problem is there is no more money.  In his blog post he tells us that all he needs is:-
$26 million and three more years

Here is the official report from the University:- 
Peter’s thoughts on Creatine
I started looking at Creatine because it appears to stimulate IGF-1 (insulin-like growth factor 1).  This is not a fact well-known to endocrinologists, but it is very well known to athletes and body builders.  They take Creatine orally and it stimulates muscle growth.  Research has even measured the change in IGF-1 in muscle tissue resulting from Creatine supplementation.

In a recent post I pointed out that IGF-1 is itself being used in autism trials, as is a novel Australian analog of IGF-1 [1-3] called NNZ-2566.  The big advantage of NNZ-2566 is that it is taken orally.

The release of IGF-1 is stimulated by growth hormone GH.  Secretion of growth hormone (GH) in the pituitary is regulated by the hypothalamus, which release the peptides Growth hormone-releasing hormone (GHRH) and Growth hormone-inhibiting hormone (GHIH) into the blood surrounding the pituitary. GH release in the pituitary is primarily determined by the balance of these two peptides, which in turn is affected by many physiological stimulators (e.g., exercise, nutrition, sleep) and inhibitors (e.g., free fatty acids) of GH secretion.
Stimulators of growth hormone (GH) secretion include:
  • peptide hormones
    • GHRH  through binding to the growth hormone-releasing hormone receptor
    • ghrelin through binding to growth hormone secretagogue receptors
  • sex hormones
    • increased androgen secretion during puberty (in males from testis and in females from adrenal cortex)
    • estrogen
  • clonidine and L-DOPA by stimulating GHRH release

·         α4β2 nicotinic agonists, including nicotine, which also act synergistically with clonidine 
      (Interestingly clonidine is a drug used for ADHD, or autism-lite, as I call it)

Factors that are known to cause variation in the levels of (GH) and IGF-1 in the circulation include: genetic make-up, the time of day, age, sex, exercise status, stress levels, nutrition level and body mass index (BMI), disease state, race, estrogen status and xenobiotic intake. The later inclusion of xenobiotic intake as a factor influencing GH-IGF status highlights the fact that the GH-IGF axis is a potential target for certain endocrine disrupting chemicals. These are chemicals found in both household and industrial products that are known to interfere with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for development, behavior, fertility, and maintenance of normal cell metabolism. 
Based on my earlier primary research, I am pretty sure that in the sub-type of autism I am dealing with, there is a deficiency of either GH or TRH, in the brain.  As I result, I am interested in mention of these hormones.

 SHANK3 deficiency
(also known as 22q13 Deletion Syndrome or Phelan-McDermid Syndrome)

IGF-1 is being trialled at Mount Sinai Hospital in New York in autistic children with SHANK3 deficiency.  In true “art” rather than “science” approach, the plan is then to trial IGF-1 on children without SHANK3 deficiency.

Here is a good explanation.
If you live in the Big Apple:-

Where Can I Get Testing?

The Icahn School of Medicine at Mount Sinai offers genetic testing for Phelan-McDermid Syndrome/22q13 Deletion Syndrome and for SHANK3 mutations. A blood sample is needed to conduct the test. For more information about testing, visit The Seaver Autism Center, call (212) 241-0961  

It appears that SHANK3 deficiency accounts for about 1% of autism cases.
If, as is hoped, IGF-1 turns out to be a useful therapy in SHANK3 deficient children, it will be tried on all ASD kids.  If it works, then what was the relevance of SHANK3 in the first place?   It seems pretty odd to me.  I think most likely our current understanding of genetics is so basic, as to be flawed.

I am working via observation, rather than genetics; I know what circumstances produce near neurotypical behaviour, I just need to understand what is going on biologically.  This is how I ended up with TRH and/or GH.

Well if the Mount Sinai study is successful, as it probably will be, we should find Dr Clark in Cincinnati and give him $26 million.  Then we put creatine and cyclocreatine in a pill and give it to ALL people with ASD, since 99% will never get their sub-type diagnosed. 

Either the creatine, the cyclocreatine or the extra IGF-1 will do some good, depending on the sub-type – something for everyone. And no needles.