Showing posts with label Rett Sydrome. Show all posts
Showing posts with label Rett Sydrome. Show all posts

Wednesday, 21 September 2022

Pentoxifylline and cGP (an IGF-1 normalizer) from Blackcurrants, for Autism?



Readers may be wondering at what point Peter will run out of things to write about.  I do sometimes wonder the same thing. I was going to also write about Loperamide (Imodium), but the post would have been too long. Next time!


Pentoxifylline has been in use to treat autism for 50 years. The original studies did suggest its effect was greatest among small children.  I have been in some discussions with a US psychiatrist, Dr Powell, who is a big fan of the off-label use of this drug to affect the brain in adults.  He has even written a book on the subject.

My previous posts on Pentoxifylline can be found here:

Dr Powell’s patients with autism tend to be older children, not the toddlers who did well in clinical trials in Japan in the 1970s.  He sees significant improvement in many, but not all, of his patients with autism.  The parents report improved social interactions and having higher-level discussions with their child.

What is notable is that he uses frequent dosing, 4 times a day, always after food to avoid the GI side effects.

Pentoxifylline is inexpensive, but its effect does not last long, hence the frequent dosing.  Some people take taking this drug 5-6 times a day.

Pentoxifylline has multiple modes of action, it should increase blood flow to the brain and it is broadly anti-inflammatory.  It is a non-selective PDE inhibitor, normally used treat muscle pain in people with peripheral artery disease. It increases red blood cell flexibility and it reduces the viscosity of blood.

There are PDEs 1 to 11. It all gets quite complicated, for example PDE1 subtype A2 has a potential role in neurodegenerative diseases, including:

·        Parkinson's disease

·        Axonal neurofilament degradation

·        Motorneuronal degradation

·        Neuronal ischemia

·        Alzheimer's disease

·        Epilepsy

Recall that PDE4 inhibitors are used to treat asthma and COPD. We can potentially repurpose those to improve myelination in MS, or autism, and at specific low doses they can improve cognition.


cGP (from Black Currants)

I did write quite a lot in this blog about growth factors and autism.  The familiar ones are BDNF, NGF and IGF-1, but there are many more. 

My previous posts on IGF-1 can be found here:

We know that growth signaling in autism is disturbed, but it is not simple.  As the disease progresses (the fetus develops, the baby is born and grows into a toddler) the imbalance in growth signaling changes.  This means that what would be helpful in a 6 month old baby might well be inappropriate in a 6 year old.  This is a good example of what I call the what, when and where of treating autism. Here it is the “when” that matters.

Some people lack BDNF while others have too much. Very possibly, this changes over time in the same child.

One possible therapy for autism is injections of IGF-1 (Insulin-like Growth Factor 1).  IGF-1 plays an important role in childhood growth.

A synthetic analog of IGF-1 is used in children for the treatment of growth failure.  This drug called Mecasermin was used in autism trials and in Rett syndrome trials.

In Rett syndrome the search has been on for an oral therapy.

Trofinetide (NNZ-2566) is a potential therapy for Rett syndrome being developed by Neuren Pharmaceuticals in Australia.

Trofinetide is derived from IGF-1.

Trofinetide got to phase 2 trials as a therapy for Fragile-X in 2015.

The second product in development at Neuren is NNZ-2591.  It is aimed at normalizing the level of IGF-1.

This is in the pipeline to treat:

  • Phelan-McDermid syndrome (Shank3 gene and others not working)
  • Angelman syndrome (UBE3A gene not working)
  • Pitt Hopkins syndrome (TCF4 gene not working)
  • Prader-Willi syndrome (MAGEL2 gene and others not working)


What is NNZ-2591?

It is an analogue (modified version) of cyclic glycine proline (cGP)

Cyclic glycine-proline (cGP), a metabolite of IGF-1, is neuroprotective through improving IGF-1 function.

There is also research focused on Parkinson’s and Alzheimer’s where it seems that cGP is reduced.

In New Zealand they found that supplementation of Blackcurrant anthocyanins (pigments) increased cGP in the spinal fluid of patients with Parkinson’s.

This also led the way to the idea of increasing cGP as means of protecting the brain during aging. There is now a commercial OTC product in New Zealand to do just this.

Our reader Daniel, who has a daughter with Rett syndrome, is assessing the benefit of cGP, using the OTC product cGPMAX. The results so far are promising.

Rett is very specific because we know for sure that IGF-1 and NGF are disturbed.

Is cGP going to be beneficial in broader autism?  May be yes, but we come back to the what, when and where.  It may well depend on when a specific person takes it.  We have both hypoactive pro-growth signalling autism and hyperactive pro-growth signalling autism.



Unfortunately, what the clever researchers who came up with the above concept did not consider is that you may start out hyper in the womb and switch to hypo a few short years later.



Frequently dosed Pentoxifylline looks like a potentially interesting therapy for many with autism, including some with high IQ.  Take note our Aspie readers.

Daniel’s idea to look at the Neuren’s non-Rett therapy as a Rett therapy is interesting.  In effect you do not need to wait for the Australian drug, you can hop across the Tasman Sea to New Zealand and use their cGP supplement, developed for protection against dementia.

You would also think that parents of children with:

  • Phelan-McDermid syndrome (Shank3 gene and others not working)
  • Angelman syndrome (UBE3A) gene not working)
  • Pitt Hopkins syndrome (TCF4 gene not working)
  • Prader-Willi syndrome (MAGEL2 gene and others not working)

might want to follow Daniel’s lead.

As you can see, there is a lot of trial and error in science.  Back in 2009 NNZ-2566 was in clinical trials for the treatment of cognitive deficits following traumatic brain injury.  That must not have worked out.  Fragile-X did not work out and now it is phase 3 for Rett girls, which seems to be going well.


IGF-1 for old people

The same growth factor IGF-1 that is key during development also plays a key role in aging. Dr Jian Guan made a world first discovery. She discovered that cGP (cyclic Glycine-Proline) was responsible for controlling the IGF-1 hormone in our body. Thus by increasing the level of cGP in our body, the cGP will essentially command the IGF-1 to build more blood vessels.

Dr Jian Guan, was then recognised as the world-wide authority on cGP. In 2017 she discovered that New Zealand blackcurrants contained high volumes of natural cGP which could regulate optimum levels of IGF-1 in the body.

So now we have Antipodeans/Kiwis fending off dementia, and potentially metabolic syndrome, by taking their locally made cGPMax.

Will it help you case of autism? Who knows, but if it does not, just give the leftover pills to Grandma, Granddad or take them yourself!


All the supporting papers from New Zealand.


Wednesday, 2 February 2022

Genetic Mutations vs Differentially Expressed Genes (DEGs) in Autism


Genes make proteins and you need the right amount in the right place
at the right time.

I should start this post by confessing to not having carried out genetic testing on Monty, now aged 18 with autism.  When I did mention this to one autism doctor at a conference, I was surprised by her reply:- “ You did not need to.  Now there’s no point doing it”.

I got lucky and treated at least some of Monty’s Differentially Expressed Genes (DEGs) by approaching the problem from a different direction.

People do often ask me about what diagnostic tests to run and in particular about genetic testing.  In general, people have far too high expectations regarding such tests and assume that there will be definitive answers, leading to effective therapeutic interventions.

I do include an interesting example today where parent power is leading a drive towards an effective therapeutic intervention in one single gene type of autism.  The approach has been to start with the single gene that has the mutation and look downstream at the resulting Differentially Expressed Genes (DEGs). The intervention targets one of the DEGs and not the mutated gene itself.

This is a really important lesson.

It can be possible to repurpose existing drugs to treat DEGs quite cheaply.  Many DEGs encode ion channels and there are very many existing drugs that affect ion channels.

Entirely different types of autism may share some of the same DEGs and so benefit from the same interventions.


Genetic Testing 

Genetic testing has not proved to be the holy grail in diagnosing and treating autism, but it remains a worthwhile tool at a population level (i.e. maybe not in your specific case).  What matters most of all are Differentially Expressed Genes (DEGs), which is something different.

A paper was recently published that looked into commercially available genetic testing.  Its conclusion was similar to my belief that you risk getting a “false negative” from these tests, in other words they falsely conclude that there is no genetic basis for the person’s symptoms of autism. 


Brief Report: Evaluating the Diagnostic Yield of Commercial Gene Panels in Autism

Autism is a prevalent neurodevelopmental condition, highly heterogenous in both genotype and phenotype. This communication adds to existing discussion of the heterogeneity of clinical sequencing tests, “gene panels”, marketed for application in autism. We evaluate the clinical utility of available gene panels based on existing genetic evidence. We determine that diagnostic yields of these gene panels range from 0.22% to 10.02% and gene selection for the panels is variable in relevance, here measured as percentage overlap with SFARI Gene and ranging from 15.15% to 100%. We conclude that gene panels marketed for use in autism are currently of limited clinical utility, and that sequencing with greater coverage may be more appropriate.


To save time and money, the commercial gene panels only test genes that the company defines as autism genes.  There is no approved list of autism genes. 

You have more than 20,000 genes and very many are implicated directly, or indirectly, in autism and its comorbities. To be thorough you need Whole Exome Sequencing (WES), where you check them all.  

There are tiny mutations called SNPs ("snips") which you inherit from your parents; there are more than 300 million known SNPs and most people will carry 4-5 million.  Some SNPs are important but clearly most are not.  Some SNPs are very common and some are very rare. 

Even WES only analyses 2% of your DNA, it does not consider the other 98% which is beyond the exome.  Whole Genome Sequencing (WGS) which looks at 100% of your DNA will be the ideal solution, but at some time in the future.  The interpretation of WES data is often very poor and adding all the extra data from WGS is going to overwhelm most people involved. 

Today we return to the previous theme of treating autism by treating the downstream effects caused by Differentially Expressed Genes (DEGS).

Genetics is very complicated and so people assume that is must be able to provide answers. For a minority of autism current genetics does indeed provide an answer, but for most people it does not.

Early on in this blog I noted so many overlaps between the genes and signaling pathways that drive cancer and autism, that is was clear that to understand autism you probably first have to understand cancer; and who has time to do that!

Some people’s cancer is predictable. Chris Evert, the American former world No. 1 tennis player, announced that she has ovarian cancer.  Her sister had exactly the same cancer.  Examining family history can often yield useful information and it is a lot less expensive that genetic testing.  Most people’s cancer is not so predictable; sure if you expose yourself to known environmental triggers you raise its chances, but much appears to be random.  Cancer, like much autism, is usually a multiple hit process. Multiple events need to occur and you may only need to block one of them to avoid cancer. We saw this with a genetic childhood leukemia that you can prevent with a gut bacteria. 

Learning about Autism from the 3 Steps to Childhood Leukaemia

What is not random in cancer are the Differentially Expressed Genes (DEGs).

We all carry highly beneficial tumor suppressing genes, like the autism/cancer gene PTEN.  You would not want to have a mutation in one of these genes.

What happens in many cancers is that the individual carries two good copies of the gene like PTEN, but the gene is turned off. For example, in many people with prostate cancer, the tumor suppressor gene PTEN is turned off in that specific part of the body.  There is no genetic mutation, but there is a harmful Differentially Expressed Gene (DEG). If you could promptly turn PTEN expression back on, you would suppress the cancer.

Not surprisingly, daily use of drugs that increase PTEN expression is associated with reduced incidence of PTEN associated cancer.  Atorvastatin is one such drug.


DEGs are what matter, not simply mutations


In many cases genetic mutations are of no clinical relevance, we all carry several on average.  In some cases they are of immediate critical relevance.  In most cases mutations are associated with a chance of something happening, there is no certainty and quite often further hits/events/triggers are required.

A good example is epilepsy. Epilepsy is usually caused by an ion channel dysfunction (sodium, potassium or calcium) that is caused by a defect in the associated gene. Most people are not born with epilepsy, the onset can be many years later.  Some parents of a child with autism/epilepsy carry the same ion channel mutation but remain unaffected. 


Follow the DEGs from a known mutation 

There is a vanishingly small amount of intelligent translation of autism science to therapy, or even attempts to do so.  I set out below an example of what can be done.


Pitt Hopkins (Haploinsufficiency of TCF4) 

The syndrome is caused by a reduction in Transcription factor 4, due to mutation in the TCF4 gene.  One recently proposed therapy is to repurpose the cheap calcium channel blocker Nicardipine. Follow the rationale below.


  means down regulated

↑ means up regulated

1.     Gene/Protein TCF4 (Transcription Factor 4) ↓↓↓↓

2.     Genes SCN10a  ↑↑    KCNQ1 ↑↑

3.     Encoding ion channels  Nav1.8   ↑↑     Kv7.1   ↑↑

4.     Repurpose approved drugs as inhibitors of Kv7.1 and Nav1.8 

5.     High throughput screen (HTS) of 1280 approved drugs.

6.     The HTS delivered 55 inhibitors of Kv7.1 and 93 inhibitors of Nav1.8

7.     Repurposing the Calcium Channel Inhibitor Nicardipine as a Nav1.8 inhibitor 


The supporting science: 

Psychiatric Risk Gene Transcription Factor 4 Regulates Intrinsic Excitability of Prefrontal Neurons via Repression of SCN10a and KCNQ1



•TCF4 loss of function alters the intrinsic excitability of prefrontal neurons 

TCF4-dependent excitability deficits are rescued by SCN10a and KCNQ1 antagonists 

TCF4 represses the expression of SCN10a and KCNQ1 ion channels in central neurons 

•SCN10a is a potential therapeutic target for Pitt-Hopkins syndrome


Nav1.8 is a sodium ion channel subtype that in humans is encoded by the SCN10A gene

Kv7.1 (KvLQT1) is a potassium channel protein whose primary subunit in humans is encoded by the KCNQ1 gene.


Transcription Factor 4 (TCF4) is a clinically pleiotropic gene associated with schizophrenia and Pitt-Hopkins syndrome (PTHS).  

SNPs in a genomic locus containing TCF4 were among the first to reach genome-wide significance in clinical genome-wide association studies (GWAS) for schizophrenia  These neuropsychiatric disorders are each characterized by prominent cognitive deficits, which suggest not only genetic overlap between these disorders but a potentially overlapping pathophysiology.

We propose that these intrinsic excitability phenotypes may underlie some aspects of pathophysiology observed in PTHS and schizophrenia and identify potential ion channel therapeutic targets.

Given that TCF4 dominant-negative or haploinsufficiency results in PTHS, a syndrome with much more profound neurodevelopmental deficits than those observed in schizophrenia, the mechanism of schizophrenia risk associated with TCF4 is presumably due to less extreme alterations in TCF4 expression at some unknown time point in development

The pathological expression of these peripheral ion channels in the CNS may create a unique opportunity to target these channels with therapeutic agents without producing unwanted off-target effects on normal neuronal physiology, and we speculate that targeting these ion channels may ameliorate cognitive deficits observed in PTHS and potentially schizophrenia.



Disordered breathing in a Pitt-Hopkins syndrome model involves Phox2b-expressing parafacial neurons and aberrant Nav1.8 expression

Pitt-Hopkins syndrome (PTHS) is a rare autism spectrum-like disorder characterized by intellectual disability, developmental delays, and breathing problems involving episodes of hyperventilation followed by apnea. PTHS is caused by functional haploinsufficiency of the gene encoding transcription factor 4 (Tcf4). Despite the severity of this disease, mechanisms contributing to PTHS behavioral abnormalities are not well understood. Here, we show that a Tcf4 truncation (Tcf4tr/+) mouse model of PTHS exhibits breathing problems similar to PTHS patients. This behavioral deficit is associated with selective loss of putative expiratory parafacial neurons and compromised function of neurons in the retrotrapezoid nucleus that regulate breathing in response to tissue CO2/H+. We also show that central Nav1.8 channels can be targeted pharmacologically to improve respiratory function at the cellular and behavioral levels in Tcf4tr/+ mice, thus establishing Nav1.8 as a high priority target with therapeutic potential in PTHS. 


Repurposing Approved Drugs as Inhibitors of Kv7.1 and Nav1.8 To Treat Pitt Hopkins Syndrome


Pitt Hopkins Syndrome (PTHS) is a rare genetic disorder caused by mutations of a specific gene, transcription factor 4 (TCF4), located on chromosome 18. PTHS results in individuals that have moderate to severe intellectual disability, with most exhibiting psychomotor delay. PTHS also exhibits features of autistic spectrum disorders, which are characterized by the impaired ability to communicate and socialize. PTHS is comorbid with a higher prevalence of epileptic seizures which can be present from birth or which commonly develop in childhood. Attenuated or absent TCF4 expression results in increased translation of peripheral ion channels Kv7.1 and Nav1.8 which triggers an increase in after-hyperpolarization and altered firing properties.


We now describe a high throughput screen (HTS) of 1280 approved drugs and machine learning models developed from this data. The ion channels were expressed in either CHO (KV7.1) or HEK293 (Nav1.8) cells and the HTS used either 86Rb+ efflux (KV7.1) or a FLIPR assay (Nav1.8).


The HTS delivered 55 inhibitors of Kv7.1 (4.2% hit rate) and 93 inhibitors of Nav1.8 (7.2% hit rate) at a screening concentration of 10 μM. These datasets also enabled us to generate and validate Bayesian machine learning models for these ion channels. We also describe a structure activity relationship for several dihydropyridine compounds as inhibitors of Nav1.8.


This work could lead to the potential repurposing of nicardipine or other dihydropyridine calcium channel antagonists as potential treatments for PTHS acting via Nav1.8, as there are currently no approved treatments for this rare disorder.


Repurposing the Dihydropyridine Calcium Channel Inhibitor Nicardipine as a Nav1.8 inhibitor in vivo for Pitt Hopkins Syndrome

Individuals with the rare genetic disorder Pitt Hopkins Syndrome (PTHS) do not have sufficient expression of the transcription factor 4 (TCF4) which is located on chromosome 18. TCF4 is a basic helix-loop-helix E protein that is critical for the normal development of the nervous system and the brain in humans. PTHS patients lacking sufficient TCF4 frequently display gastrointestinal issues, intellectual disability and breathing problems. PTHS patients also commonly do not speak and display distinctive facial features and seizures. Recent research has proposed that decreased TCF4 expression can lead to the increased translation of the sodium channel Nav1.8. This in turn results in increased after-hyperpolarization as well as altered firing properties. We have recently identified an FDA approved dihydropyridine calcium antagonist nicardipine used to treat angina, which inhibited Nav1.8 through a drug repurposing screen.


All of the above was a parent driven process.  Well done, Audrey!

Questions remain.

Is Nicardipine actually beneficial to people with Pitt Hopkins Syndrome? Does it matter at what age therapy is started? What about the Kv7.1 inhibitor?



Genetics is complicated, ion channel dysfunctions are complicated; but just a superficial understanding can take you a long way to understand autism, epilepsy and many other health issues.

There is a great deal in this blog about channelopathies/ion channel dysfunctions.

Almost everyone with autism has one or more channelopathies. Most channelopathies are potentially treatable.

Parents of children with rare single gene autisms should get organized and make sure there is basic research into their specific biological condition.  They need to ensure that there is an animal model created and it is then used to screen for existing drugs that may be therapeutic.  I think they also need to advocate for gene therapy to be developed.  This all takes years, but the sooner you start, the sooner you will make an impact.

Very likely, therapies developed for some single gene autisms will be applicable more broadly.  A good example may be the IGF-1 derivative Trofinetide, for girls with Rett Syndrome. IGF-1 (Insulin-like growth factor 1) is an important growth factor that is required for proper brain development. In the brain, IGF-1 is broken down into a protein fragment called glypromate (GPE). Trofinetide is an orally available version of GPE.

The MeCP2 protein controls the expression of several genes, such as Insulin-like Growth Factor 1 (IGF1), brain-derived neurotrophic factor (BDNF) and N-methyl-D-aspartate (NMDA).  All three are implicated in broader autism.

In girls with Rett Syndrome the genetic mutation is in the gene MeCP2, but one of the key DEGs (differentially expressed genes) is the FXYD1; it is over-expressed. IGF-1 supresses the activity of FXYD1 and hopefully so does Trofinetide.  Not so complicated, after all!

Medicine is often driven by the imperative to do no harm.

In otherwise severely impaired people, perhaps the imperative should be to try and do some good.

In medicine, time is of the essence; doctors in the ER can be heard to say "Stat!", from the Latin word for immediately, statim.  

How about some urgency in translating autism science into therapy? But then, what's the hurry? Why rock the boat?

On an individual basis, much is already possible, but you will have to do most of the work yourself - clearly a step too far for most people.



Friday, 6 March 2020

Calcium Folinate (Leucovorin) and Afobazole for Autism? Good, but …

Dr Frye is embarking on a multi-million dollar trial of Calcium Folinate (Leucovorin) to improve speech in autism.  I just completed my much humbler trial of a cheap generic Calcium Folinate.

I determined it was far cheaper and simpler to make a trial, than arrange for the blood test.  The other reason is that I note in the US they are prescribing Leucovorin, even if you test negative in the test for autoantibodies.

Dr Frye thinks many people with autism have low levels of folate inside their brain due to antibodies blocking folate crossing the blood brain barrier.  He even suggests that perhaps the source of these antibodies is your gut and they are produced as a reaction to cow’s milk.

I wondered why speech would be so directly affected by folate, but speech is something that is very noticeable and measurable.

I used 30mg of calcium folinate at breakfast and 15mg in the evening.

After a few days there was very clearly more speech. On several occasions I asked Monty a question, even without facing him eye to eye, and he gave a very much longer response than usual. The response was more like what he would produce if writing with a pencil and paper.

The problem was that three times during the trial he hit me, which is not his typical behavior. Aggression is a listed side effect of high dose calcium folinate.

Excerpt from Dr Frye’s colleague, Dr Dan Rossignol:

Dan Rossignol’s  Presentation at Synchrony 2019 | November 8, 2019

Folinic acid

• The good: Improvements in expressive speech, play skills, social skills, receptive language, attention, stereotypy

• The bad: Hyperactivity, self-stimulatory behaviors, aggression

Calcium Folinate (Leucovorin) is expensive in the US, but very much cheaper in some other countries, so it would be a viable therapy for many people.

Is there a lower dosage where you get the speech benefit without getting hit? I rather doubt it. It did actually try 15mg a day, a while back and saw no effect at all.

Since we do not really know why Calcium Folinate improves speech in particular, I doubt we can say why it produces aggression.

My old post from 2016:-

Clinical Trial of Mega-dose Folinic Acid in Autism

The new trial that is planned:-

The primary objective of this study is to evaluate the cognitive and behavioral effects of liquid leucovorin calcium on young children with autism spectrum disorder (ASD) and determine whether it improves language as well as the core and associated symptoms of ASD. The investigators will enrol 80 children across two sites, between the ages of 2.5 and 5 years, with confirmed ASD and known language delays or impairments. Participation will last approximately 26 weeks from screening to end of treatment.


Afobazole is the cheap Russian OTC treatment for anxiety that works as a sigma-1R agonist.  It has an effect on NMDA receptors.

Afobazole was covered in two recent posts.

ER Stress and Protein Misfolding in Autism (and IP3R again) and perhaps what to do about it -Activation of Sigma-1 Chaperone Activity by Afobazole?

Afobazole is primarily used to treat mild anxiety.  Indeed it appears that sigma-1 receptor activation ameliorates anxiety through NR2A-CREB-BDNF signalling.  NR2A is a sub-unit of NMDA receptors.

Hundreds of millions of dollars are being spent in the US to develop a safe sigma-1R agonist (Anavex 2-73). This drug is being trialed in various autisms (Rett, Fragile X and Angelman syndromes), Parkinson’s and Alzheimer’s.

Afobazole should reduce ER Stress and protein misfolding, making it an interesting potential therapy for many neurological conditions.

I did raise the issue as to whether Afobazole may affect the Excitatory-Inhibitory (E/I) imbalance that is present in bumetanide-responsive autism.

It turns out that in my trial, Afobazole was beneficial in reducing anxiety, it just takes the edge off - nothing drastic.  After several weeks I did notice a slight reduction in cognition, this was only really evident when working on maths. It was more noticeable on cessation.  If I did not teach Monty maths, all I would have noticed was the reduction in anxiety.  When I stopped Afobazole, Monty’s assistant commented how clever he was at school.

Since we are trying to keep up with typical children in academic work at mainstream school, cognitive function is the priority and so no more Afobazole.


I hope the millions of dollars spent on the Calcium Folinate (Leucovorin) trials produce some tangible results. Speech clearly is the area where it shows an effect, I think it has other effects that are less measurable.  It did seem to have an effect on what I would describe as “initiative”, which is completing tasks independently that otherwise you might ask for help to complete.

If you could have the benefits of Calcium Folinate (Leucovorin) without the negative effects, that would indeed be very interesting.

Perhaps giving Calcium Folinate (Leucovorin) to very young non-verbal children will give them a nudge to start speaking.  In those little children you would likely be less concerned by some aggression - they do not hit very hard.

Afobazole also has a place; anxiety is a problem in much autism and for many people a small drop in cognition, if it indeed occurs, is not such a problem.  Long term Afobazole use might produce benefits relating to reduced ER stress and less protein misfolding.

If I had a child with Rett, Fragile X or Angelman syndromes, I would definitely trial Afobazole, since the new American sigma-1R agonist (Anavex 2-73) is not yet available and I suppose will cost 100-200 times more than the Russian drug.

I think you need to find therapies free of any troubling side effects; otherwise in trying to solve one problem, you just create two new ones.