Showing posts with label Phelan-McDermid Syndrome. Show all posts
Showing posts with label Phelan-McDermid Syndrome. 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.


Thursday 31 March 2016

Intranasal Insulin for Improved Mood and Cognition


This post follows on the previous one that raised the issue of brain-specific insulin sensitivity being a common feature of neurological diseases/disorders.

It appears to be much more than just a rare possibility.   There have been numerous studies and even more are ongoing.

Intranasal insulin has even been tried one single-gene type of autism (Phelan-McDermid Syndrome) and in autism’s big brothers, bipolar and schizophrenia.

I did look for trials in children with Down Syndrome, since here is a direct link to Alzheimer’s, but there is just a trial in adults in progress.

There was an early trial in typical adults which is interesting since it found not only a cognitive improvement but also improved mood, so perhaps it should be trialed in adults with depression.  In the US, interestingly, T3 thyroid hormone is sometimes given off-label for depression and some antidepressants increase the conversion of the pro-hormone T4 to T3 in the brain.  I think central hypothyroidism is likely a feature of some neurological disorders, as I proposed in an earlier post.

I think it would be well worth trialing intranasal insulin in idiopathic Autism and, separately, idiopathic Asperger’s.  I am surprised nobody has done it. I really think Autism and Asperger’s  should be separated, since while we sometimes see the same therapy helps in both, sometimes there are Asperger-specific therapies, like Baclofen.

A small number of readers of this blog do follow the science and engage in some experimentation at home.  I think given what some people have already tried, intranasal insulin is not at all far fetched, you just need a metered dose nasal spray, insulin and the correct amount of dilutant/diluent, as in the trials.

Insulin and IGF-1 (insulin-like growth factor 1)

There are autism trials underway using subcutaneous injections of IGF-1 and also oral IGF-1 analogs.

IGF-1 is a primary mediator of the effects of growth hormone (GH). Growth hormone is made in the anterior pituitary gland, is released into the blood stream, and then stimulates the liver to produce IGF-1. IGF-1 then stimulates systemic body growth, and has growth-promoting effects on almost every cell in the body,

Insulin levels affect levels of growth hormone (GH) and IGF-1.

We know that various growth factors (NGF, BDNF, IGF-1 etc.) in people with autism can be disturbed, but there is both hypo and hyper.

We also know that the level of hormones measured in the blood can be very different to those in the brain/CNS.  This means that having blood tests indicating  high serotonin, thyroid T3, IGF-1 etc. does not tell you anything about the level within the brain.  Quite possibly they may be the opposite.

It would seem to be hugely preferable to target the brain directly, rather than the whole body.

The lack of side effects in the numerous studies of intranasal insulin is very encouraging.

Healthy Neurotypical Adults

Declarative memory in humans without causing systemic side effects like hypoglycaemia. The improvement of memory in the eighth week of treatment corroborates previous findings of improved memory function following acute intravenous administration of the peptide both in healthy subjects (Kern et al., 2001) and in patients with Alzheimer’s disease (Craft et al., 1999). In addition, intranasal insulin positively affected mood in our subjects. The improving effect of subchronic intranasal insulin administration appeared to be specific for hippocampus dependent declarative memory.

Our subjects in the insulin group also expressed enhanced mood. Acute intranasal intake of insulin enhanced the feelings of well-being and self-confidence, which is in accordance with previous results (Kern et al., 1999).

In summary our data indicate that prolonged intranasal intake of insulin improves both consolidation of words and general mood. These beneficial findings suggest intranasal administration of insulin as a potential treatment in patients showing memory deficits in conjunction with a lack of insulin, such as in Alzheimer’s disease

Adults with Schizophrenia

No effect of adjunctive, repeated-dose intranasal insulin treatment on psychopathology and cognition in patients with schizophrenia.



This study examined the effect of adjunctive intranasal insulin therapy on psychopathology and cognition in patients with schizophrenia.


Each subject had a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis of schizophrenia or schizoaffective disorder and been on stable antipsychotics for at least 1 month. In an 8-week randomized, double-blind, placebo-controlled study, subjects received either intranasal insulin (40 IU 4 times per day) or placebo. Psychopathology was assessed using the Positive and Negative Syndrome Scale and the Scale for Assessment of Negative Symptoms. A neuropsychological battery was used to assess cognitive performance. The assessment for psychopathology and cognition was conducted at baseline, week 4, and week 8.


A total of 45 subjects were enrolled in the study (21 in the insulin group and 24 in the placebo group). The mixed model analysis showed that there were no significant differences between the 2 groups at week 8 on various psychopathology and cognitive measures (P > 0.1).


Adjunctive therapy with intranasal insulin did not seem to be beneficial in improving schizophrenia symptoms or cognition in the present study. The implications for future studies were discussed.

Adults with Bipolar

A randomized, double-blind, controlled trial evaluating the effect of intranasal insulin on neurocognitive function in euthymic patients with bipolar disorder.




Neurocognitive deficits are prevalent, persistent, and implicated as mediators of functional impairment in adults with bipolar disorder. Notwithstanding progress in the development of pharmacological treatments for various phases of bipolar disorder, no available treatment has been proven to be reliably efficacious in treating neurocognitive deficits. Emerging evidence indicates that insulin dysregulation may be pertinent to neurocognitive function. In keeping with this view, we tested the hypothesis that intranasal insulin administration would improve measures of neurocognitive performance in euthymic adults with bipolar disorder.


Sixty-two adults with bipolar I/II disorder (based on the Mini International Neuropsychiatric Interview 5.0) were randomized to adjunctive intranasal insulin 40 IU q.i.d. (n = 34) or placebo (n = 28) for eight weeks. All subjects were prospectively verified to be euthymic on the basis of a total score of ≤ 3 on the seven-item Hamilton Depression Rating Scale (HAMD-7) and ≤ 7 on the 11-item Young Mania Rating Scale (YMRS) for a minimum of 28 consecutive days. Neurocognitive function and outcome was assessed with a neurocognitive battery.


There were no significant between-group differences in mean age of the subjects {i.e., mean age 40 [standard deviation (SD) = 10.15] years in the insulin and 39 [SD = 10.41] in the placebo groups, respectively}. In the insulin group, n = 27 (79.4%) had bipolar I disorder, while n = 7 (21.6%) had bipolar II disorder. In the placebo group, n = 25 (89.3%) had bipolar I disorder, while n = 3 (10.7%) had bipolar II disorder. All subjects received concomitant medications; medications remained stable during study enrollment. A significant improvement versus placebo was noted with intranasal insulin therapy on executive function (i.e., Trail Making Test-Part B). Time effects were significant for most California Verbal Learning Test indices and the Process Dissociation Task-Habit Estimate, suggesting an improved performance from baseline to endpoint with no between-group differences. Intranasal insulin was well tolerated; no subject exhibited hypoglycemia or other safety concerns.


Adjunctive intranasal insulin administration significantly improved a single measure of executive function in bipolar disorder. We were unable to detect between-group differences on other neurocognitive measures, with improvement noted in both groups. Subject phenotyping on the basis of pre-existing neurocognitive deficits and/or genotype [e.g., apolipoprotein E (ApoE)] may possibly identify a more responsive subgroup

22q13 deletion syndrome is a genetic disorder caused by deletions or rearrangements on the q terminal end (long arm) of chromosome 22. Any abnormal genetic variation in the q13 region that presents with significant manifestations typical of a terminal deletion should be diagnosed as 22q13 deletion syndrome. 22q13 deletion syndrome is often placed in the more general category of Phelan-McDermid Syndrome (abbreviated PMS), which includes some mutations and microdeletions. 

·         Absent to severely delayed speech: 99%
·         Normal to accelerated growth: 95%
·         High tolerance to pain: 77%
·         Hypotonia (poor muscle tone): 75%
·         Dysplastic toenails: 73%
·         Long eyelashes: 73%
·         Poor thermoregulation: 68%
·         Prominent, poorly formed ears: 65%
·         Large or fleshy hands: 63%
·         Pointed chin: 62%
·         Dolichocephaly (elongated head): 57%
·         Ptosis (eyelid) (droopy eyelids): 57%
·         Gastroesophageal reflux: 42%
·         Epileptic seizures: 27%
·         Kidney problems: 26%
·         Delayed ability to walk: 18%

·         Chewing on non food items: 85%
·         Delayed or unreliable toileting: 76%
·         Impulsive behaviors: 47%
·         Biting (self or others): 46%
·         Problems sleeping: 46%
·         Hair pulling: 41%
·         Autistic behaviors: 31%
·         Episodes of non-stop crying before age 5: 30%
·         Teeth grinding: (unknown) %

Intranasal insulin to improve developmental delay in children with 22q13 deletion syndrome: an exploratory clinical trial.



The 22q13 deletion syndrome (Phelan-McDermid syndrome) is characterised by a global developmental delay, absent or delayed speech, generalised hypotonia, autistic behaviour and characteristic phenotypic features. Intranasal insulin has been shown to improve declarative memory in healthy adult subjects and in patients with Alzheimer disease.


To assess if intranasal insulin is also able to improve the developmental delay in children with 22q13 deletion syndrome.


We performed exploratory clinical trials in six children with 22q13 deletion syndrome who received intranasal insulin over a period of 1 year. Short-term (during the first 6 weeks) and long-term effects (after 12 months of treatment) on motor skills, cognitive functions, or autonomous functions, speech and communication, emotional state, social behaviour, behavioural disorders, independence in daily living and education were assessed.


The children showed marked short-term improvements in gross and fine motor activities, cognitive functions and educational level. Positive long-term effects were found for fine and gross motor activities, nonverbal communication, cognitive functions and autonomy. Possible side effects were found in one patient who displayed changes in balance, extreme sensitivity to touch and general loss of interest. One patient complained of intermittent nose bleeding.


We conclude that long-term administration of intranasal insulin may benefit motor development, cognitive functions and spontaneous activity in children with 22q13 deletion syndrome.

For intranasal administration, insulin (40 IU/ml; Actrapid, Novo Nordisk, Mainz, Germany) was diluted with 0.9% saline solution to a concentration of 20 IU/ml so that each 0.1 ml puff with the nasal atomizer (Aero Pump, Hochheim, Germany) contained a dose of 2 IU insulin. Subjects received one dose of 2 IU insulin per day during the first 3 days according to the standard subcutaneous insulin therapy in children with type 1 diabetes mellitus. In three-day intervals, administration was increased gradually, until the final dosage of about 0.5-1.5 IU/kg/d (TID)

As with idiopathic autism there is interest in using the related IGF-1 as a therapy.

A pilot controlled trial of insulin-like growth factor-1 in children with Phelan-McDermid syndrome


Autism spectrum disorder (ASD) is now understood to have multiple genetic risk genes and one example is SHANK3. SHANK3 deletions and mutations disrupt synaptic function and result in Phelan-McDermid syndrome (PMS), which causes a monogenic form of ASD with a frequency of at least 0.5% of ASD cases. Recent evidence from preclinical studies with mouse and human neuronal models of SHANK3 deficiency suggest that insulin-like growth factor-1 (IGF-1) can reverse synaptic plasticity and motor learning deficits. The objective of this study was to pilot IGF-1 treatment in children with PMS to evaluate safety, tolerability, and efficacy for core deficits of ASD, including social impairment and restricted and repetitive behaviors.


Nine children with PMS aged 5 to 15 were enrolled in a placebo-controlled, double-blind, crossover design study, with 3 months of treatment with IGF-1 and 3 months of placebo in random order, separated by a 4-week wash-out period.


Compared to the placebo phase, the IGF-1 phase was associated with significant improvement in both social impairment and restrictive behaviors, as measured by the Aberrant Behavior Checklist and the Repetitive Behavior Scale, respectively. IGF-1 was found to be well tolerated and there were no serious adverse events in any participants.


This study establishes the feasibility of IGF-1 treatment in PMS and contributes pilot data from the first controlled treatment trial in the syndrome. Results also provide proof of concept to advance knowledge about developing targeted treatments for additional causes of ASD associated with impaired synaptic development and function.

Drug administration

IGF-1 (Increlex; Ipsen Biopharmaceuticals, Inc) is an aqueous solution for injection containing human insulin-like growth factor-1 (rhIGF-1) produced by recombinant DNA technology. Placebo consisted of saline prepared in identical bottles by the research pharmacy at Mount Sinai. We received an Investigational New Drug exemption from the Food and Drug Administration (#113031) to conduct this trial in children with PMS. Based on the package insert for Increlex, dose titration was initiated at 0.04 mg/kg twice daily by subcutaneous injection, and increased, as tolerated, every week by 0.04 mg/kg per dose to a maximum of 0.12 mg/kg twice daily. This titration was justified based on our preclinical data, which indicated that 0.24 mg/kg/day is effective in reversing electrophysiological deficits whereas 0.12 mg/kg/day was not as effective[21]. We aimed to reach the therapeutic dose as quickly as is safe and tolerated in order to allow maximum time for clinical improvement. Doses could be decreased according to tolerability by 0.04 mg/kg per dose. Medication was administered twice daily with meals, and preprandial glucose monitoring was performed by parents prior to each injection throughout the treatment period. Parents were carefully trained in finger stick monitoring, symptoms of hypoglycemia, and medication administration.

Down Syndrome

The ongoing Down Syndrome trial is in adults.  As mentioned earlier, a feature of the syndrome is the likely early onset of Alzheimer’s, so not surprisingly if intranasal insulin helps people with Alzheimer’s it makes sense to trial it on people with Down Syndrome.
I think it makes sense to trial it on young people with Down Syndrome, prior to the onset of Alzheimer’s.

This study is a single center, randomized, double-blind, placebo-controlled, cross-over pilot study designed to assess the safety of intranasally (IN) delivered glulisine versus placebo in patients with DS. Subjects will be randomized into this cross-over study and within subject comparisons conducted between single treatment of intranasal insulin glulisine and single treatment of intranasal placebo

The SNIFF (Study of Nasal Insulin in the Fight against Forgetfulness) Trials

The large clinical trials all relate to Alzheimer’s.  The big trial, SNIFF INI, will last for 18 months, but they are also making shorter trials using different types of insulin.  There is  SNIFF Quick to test fast acting insulin and SNIFF long to test the long acting type.

The big 18 month study.


I think in a couple of decade’s time, it will be widely recognized that various physiological states exist in many complex diseases and while it may not be possible to cure those conditions, you can treat those altered physiological states.

In the case of autism those states might include:-

·        Oxidative stress
·        Mitochondrial stress
·        Microglial activation
·        Central hormonal dysfunction
·        Reduced brain insulin sensitivity
·        Impaired remyelination
·        Faulty GABA switch

These altered states are in addition to the specific channelopathies and other dysfunctions a particular person might have.

By applying what is learnt from other diseases we can then better treat the autism variants.  So what eventually develops from MS research in regard to remyelination can be translated to some autism variants, quite possibly that of Hannah Poling (mitochondrial disease, triggered by vaccination).

Reduced brain insulin sensitivity, where present, appears very treatable today.  I suspect some variants of autism do indeed feature reduced brain insulin sensitivity, but others will not.  There is no clever way to predict this, but it looks simple to test.