Monty in Montevideo and Recent Advances in Autism Research

It is nice to have a city named after you and Monty finally visited “his” city, Montevideo in Uruguay.

I suppose my city would be St Petersburg, which I have visited several times.

A really impressive city in Latin America is Buenos Aires; it has a very large central area with beautiful architecture. It enjoyed several decades of great wealth, the “golden age,” when the city was laid out. In 1930 there was a military coup and the party was over. It has been boom and bust ever since.

We visited what they call the Southern Cone of Latin America, which is made up of Argentina, Chile and Uruguay. We went from Buenos Aires all the way down to Tierra del Fuego.

Santiago, the capital of Chile, looks to be booming. It has a small historic centre and everything else is new.

Montevideo was more what I expected, except for the graffiti everywhere which makes it look less safe than it likely is. Uruguay has many beautiful beaches, but until you get away from the vast River Plate estuary (Río de la Plata = river of silt) and to the Atlantic ocean the water is a dirty brown colour.  Monty would not go in the water.

Southern Chile and Argentina have some stunning scenery with volcanoes, mountains and glaciers.  It looks great, but it is no longer the cheap backpacker destination it once was.

 

 

Back to the Autism Research

The highlight from the recent research comes from The RIKEN institute in Japan. It does go some way to explaining why so many people with autism appear to have nothing in their genetic results to explain their condition.

Normally, when you have your state of the art whole genome screening (WGS) the geneticist who interprets the results is looking for mutations in one of the many hundreds of known “autism genes” and nowadays, hopefully, in the non-coding areas next to them. Whole exome screening (WES) just looks at the 2% of the genome that has the instructions for how to make each of your 22,000 genes. The other 98% includes things like promoters that increase activity of a specific gene.

Many people with autism appear to show no mutations that are relevant.

The Japanese have figured out one of the reasons why this is the case. There are other reasons.

Our genetic material is not stored on something like a long role of paper, which is like a two-dimensional object.  It is a three-dimensional twisted object all folded up. As a result, the DNA physically closest to each autism gene may not be the part expected. The Japanese use the term “topologically associating domain” (TAD) to define which zones of DNA are actually interacting with each other.

They found that de novo mutations in promoters heightened the risk of ASD only when the promoters were located in TADs that contained ASD-related genes. Because they are nearby and in the same TAD, these de novo mutations can affect the expression of ASD-related genes.

This means that geneticists now need to go back to school and learn about the TAD of each autism gene. Or else just replace the geneticist with an AI generated report.

 

Mutation butterfly effect: Study reveals how single change triggers autism gene network

Researchers in the RIKEN Center for Brain Science (CBS) examined the genetics of autism spectrum disorder (ASD) by analyzing mutations in the genomes of individuals and their families. They discovered that a special kind of genetic mutation works differently from typical mutations in how it contributes to the condition. In essence, because of the three-dimensional structure of the genome, mutations are able to affect neighboring genes that are linked to ASD, thus explaining why ASD can occur even without direct mutations to ASD-related genes. This study appeared in the scientific journal Cell Genomics on January 26.

The researchers analyzed an extensive dataset of over 5,000 families, making this one of the world's largest genome-wide studies of ASD to date. They focused on TADs-;three-dimensional structures in the genome that allow interactions between different nearby genes and their regulatory elements. They found that de novo mutations in promoters heightened the risk of ASD only when the promoters were located in TADs that contained ASD-related genes. Because they are nearby and in the same TAD, these de novo mutations can affect the expression of ASD-related genes. In this way, the new study explains why mutations can increase the risk of ASD even when they aren't located in protein-coding regions or in the promotors that directly control the expression of ASD-related genes.

 

"Our most important discovery was that de novo mutations in promoter regions of TADs containing known ASD genes are associated with ASD risk, and this is likely mediated through interactions in the three-dimensional structure of the genome."  

Atsushi Takata at RIKEN CBS

 

 

Topologically associating domains define the impact of de novo promoter variants on autism spectrum disorder risk

Whole-genome sequencing (WGS) studies of autism spectrum disorder (ASD) have demonstrated the roles of rare promoter de novo variants (DNVs). However, most promoter DNVs in ASD are not located immediately upstream of known ASD genes. In this study analyzing WGS data of 5,044 ASD probands, 4,095 unaffected siblings, and their parents, we show that promoter DNVs within topologically associating domains (TADs) containing ASD genes are significantly and specifically associated with ASD. An analysis considering TADs as functional units identified specific TADs enriched for promoter DNVs in ASD and indicated that common variants in these regions also confer ASD heritability. Experimental validation using human induced pluripotent stem cells (iPSCs) showed that likely deleterious promoter DNVs in ASD can influence multiple genes within the same TAD, resulting in overall dysregulation of ASD-associated genes. These results highlight the importance of TADs and gene-regulatory mechanisms in better understanding the genetic architecture of ASD.

 

Bumetanide

 

I did come across a Chinese study with an eye-catching title:-

 

Can bumetanide be a miraculous medicine for autism spectrum disorder: Meta-analysis evidence from randomized controlled trials

 

Highlights

• Bumetanide showed significant and large effects on the overall core symptoms of ASD.
• Bumetanide’s efficacy on ASD is influenced by subjects’ age, dosage form, duration.
• Results of RCTs on bumetanide in ASD are moderated by study designs, measurement tools

A systematic search was conducted on PubMed, EMBASE, MEDLINE, PsyclNFO, Web of Science, Clinical Trials.gov, and references in reviews from the earliest available date to September 2023. Randomized controlled trials (RCTs) were identified that evaluated the efficacy of bumetanide in improving overall core symptoms (OCS) of ASD. Therefore, nine studies with 1036 participants were included in the study.

Results

Bumetanide showed significant effects on OCS of ASD (WMD = － 1.91, p = 0.006), particularly in sub-domains including relation to inanimate objects, adaption to environment changes, auditory response, near sensory responses, anxiety and hyperactivity. Moderating analysis indicated that a significant effect size of bumetanide on OCS of ASD was observed in specific subgroup, including 3–6 years old (WMD = －1.08, p = 0.008), the tablet (WMD = －2.80, p = 0.003), 3-month intervention (WMD = －2.54, p = 0.003), and the single-center studies (WMD = －2.80, p = 0.003).

Conclusions

Bumetanide has a large and significant impact on the OCS of ASD. Given the limited number and quality of included RCTs, future research should prioritize conducting large-scale trials focusing on sub-parameters or specific clinical features to comprehensively evaluate the efficacy of bumetanide in subpopulations of children with ASD.

Meanwhile, Professor Ben Ari has written another paper on why the phase 3 trial failed and has also published a book.

 

Bumetanide to treat autism spectrum disorders: are complex administrative regulations fit to treat heterogeneous disorders?

Introduction:

Extensive experimental observations suggest that the regulation of ion fluxes and, notably, chloride are impacted in autism spectrum disorders (ASD) and other neurodevelopmental disorders. The specific NKCC1 cotransporter inhibitor Bumetanide has been shown to attenuate electrophysiological and behavioral features of ASD in experimental models. Both pilot and phase 2 double-blind randomized independent trials have validated these effects with thousands of children treated successfully. Both brain imaging and eye tracking observations also validate these observations. However, final large phase 3 trials failed, with no significant differences between placebo and treated children.

Methods:

Here, I discuss the possible reasons for these failures and discuss the exclusive reliance on complex patent cooperation Treaty (PCT) regulations. Indeed, available data suggest that bumetanide responders could be identified by relying notably on EEG measures, suggesting that biological sub-populations of patients might benefit from the treatment.

Results:

These observations raise important debates on whether treating only a % of children with ASD is acceptable.

Discussion:

It is likely that in many disorders, the heterogeneity of the pathological event precludes a single general treatment for all, suggesting that trials centered on selective populations of responders might be essential for large clinical trials to succeed.

  Here is the new book:-

Treating Autism with Bumetanide

https://www.cambridgescholars.com/product/978-1-5275-1890-2/

In spite of its high incidence, extensive media coverage and major clinical burden to families, there is not a single approved European or American drug treatment of Autism Spectrum Disorders (ASDs). The dominant genetic and psychiatric approaches to treat ASDs have various limitations, suggesting that a novel global approach to understand and treat ASDs is warranted. Based on the authors’ converged expertise on brain development, ASD treatment and brain imaging, this book provides a fresh view of the disorder which is validated by experimental imaging and large clinical trials, culminating in the first large phase 3 final pediatric trial (on 400 children in EU countries and the US) using a repositioning of a drug used for decades to treat hypertension and edema. The convergence of experimental and clinical data on this disorder is unprecedented, confirming the potential of the drug to be the first pediatric treatment of ASDs.

After explaining the mechanisms underlying ASDs, we describe specific cases of children who, after treatment, considerably improved their sociability and reduced their agitation. The book also discusses the skepticism that the authors met from the tenants of pure genetics and psychiatry, and why the abyssal poverty of information on developmental disorders has hampered progress in understanding and treating ASD.

 

Bumetanide dosage is key – “wonderful effects from increasing from 0.5mg to 1mg” 

One recuring feature I have noticed from bumetanide use in the United States is the low dosage often used, as if these doctors want to show the drug is ineffective.

A reader recently contacted me about his young son who responded to the low dose of 0.5mg, but his autism doctor would not increase the dose.  The parent took matters into his own hands and increased the dose and then wrote to tell me about the “wonderful effects.”

 

Diuresis has stopped, but restarts at a lower dose

In a minority of cases bumetanide causes no diuresis. The question is whether it can have any effect in the brain if it causes no diuresis. Has the drug been absorbed at all?

One reader contacted me to tell me that her son, who has responded well to bumetanide for several years, stopped experiencing any diuresis. Then she told me that when she reduces the dose the diuresis returns.

There are many possible explanations, but perhaps those people who find bumetanide causes no diuresis should try a lower dose and see what happens.

 

Vasopressin/Desmopressin

Much of the research into the hormone vasopressin comes from Stanford. They have published a string of papers over the years. I think they are definitely on to something, but they are taking their time and may never commercialize the result.  

The very recent one is:

Vasopressin deficiency: a hypothesized driver of both social impairment and fluid imbalance in autism spectrum disorder

 

For some reason there is no abstract. 

Thanks to our reader Seth, I have now added the link below that takes you directly to  Stanford's website, which holds the full text version of the paper. 

https://med.stanford.edu/content/dam/sm/parkerlab/documents/da035ad7-7c80-41bd-a9a6-ee03a8bcc58d.pdf

The same group previously published a paper showing that people with ASD have a reduced level of vasopressin in their spinal fluid. As you can see in the chart below the level of oxytocin was normal.

There have also been successful trials using intranasal vasopressin in humans.

Cerebrospinal fluid vasopressin and symptom severity in children with autism

 

Vasopressin and oxytocin are closely related hormones and possibly some interactions are not yet fully understood.

Both these hormones can be given via a nasal spray.

 

The Bumetanide-Vasopressin interaction

Under normal circumstances you would never combine vasopressin with a diuretic.

Vasopressin stops you peeing and that it is why it is given to some children who wet their bed at night.

Bumetanide is a fast-acting diuretic that causes you to pee a lot.

So if you gave a diuretic to an elderly overweight person to reduce their blood pressure, it would be mad to also prescribe vasopressin.  The drugs are therefore contraindicated.

In autism we do not actually want the diuretic effects of bumetanide. We just want its effects on the brain.

The social and emotional beneficial effects of vasopressin have already been established by the existing Stanford research.

The combined effects of bumetanide + intranasal vasopressin might then be a win-win. Less autism and without the diuresis.

I was contacted long ago by a father whose daughter was prescribed Desmopressin, a synthetic analog of vasopressin that is an approved drug, and her autism markedly improved.

The Stanford research in humans uses a nasal spray that they have compounded specially rather than the commercially available Desmopressin.