Excitatory/Inhibitory (E/I) imbalances as a unifying, treatable, feature of severe autism that cause Cognitive Impairment, Self-Injurious Behavior (SIB) and ultimately seizures in some

 

Autism is a complex condition that manifests in a range of symptoms, from social and communication challenges to sensory sensitivities and repetitive behaviors. Researchers long ago identified a key neurobiological mechanism that underlies many of the core and associated features of autism: excitatory/inhibitory (E/I) imbalances in the brain.

These imbalances, where the delicate interplay between neuronal excitation and inhibition is disrupted, offers a unifying framework to explain certain severe manifestations of autism, including cognitive impairment, self-injurious behavior (SIB), and seizures. Understanding E/I imbalance not only sheds light on the biology of autism but also opens new avenues for targeted therapies.

 

The Role of E/I Balance in the Brain

Neuronal circuits rely on a finely tuned balance between excitatory and inhibitory signals to function properly. Excitatory neurons promote the firing of signals, enabling processes like learning, memory, and sensory integration. Inhibitory neurons, on the other hand, dampen excessive activity, ensuring stability and preventing overstimulation.

In individuals with autism, this balance is often disrupted. Overactive excitatory signaling or insufficient inhibitory control can lead to hyperexcitability in certain brain regions, contributing to behavioral and neurological symptoms. This imbalance is influenced by a range of factors, including:

• Genetic mutations in key synaptic proteins (e.g., SHANK3, SCN1A, GABA receptor subunits).
• Neuroinflammation and oxidative stress.
• Developmental disruptions in synaptic pruning or circuit formation.

 

How E/I imbalances drives severe autism symptoms

 

Cognitive Impairment

E/I imbalance affects the prefrontal cortex and hippocampus, regions critical for cognitive functions like problem-solving, memory, and attention. Disrupted neural signaling in these areas impairs synaptic plasticity—the brain’s ability to adapt and learn—which can manifest as intellectual disability in some individuals with autism.

Studies have shown that restoring E/I balance in animal models can improve cognitive deficits, highlighting its central role in intellectual development.

 

Self-Injurious Behavior (SIB)

Self-injurious behaviors, such as head-banging or skin-picking, are often linked to dysregulated sensory processing and impaired impulse control. Hyperexcitability in brain regions like the amygdala can heighten stress responses, while altered pain thresholds caused by E/I imbalance may make some individuals less sensitive to injury.

Addressing the underlying imbalance can reduce the neural hyperactivity driving these behaviors and improve emotional regulation.

 

Seizures

Seizures are a common comorbidity in autism, affecting up to 30% of individuals. They arise directly from hyperexcitability in neural networks, where excessive excitation leads to abnormal, synchronized firing of neurons. Genetic conditions like Dravet syndrome, linked to mutations in sodium channel genes (e.g., SCN1A), exemplify the connection between E/I imbalance and epilepsy.

Therapies that stabilize E/I balance, such as GABA-enhancing drugs or ion channel modulators, have shown promise in reducing seizure frequency and severity.

 

Targeting E/I Imbalance: A Path Toward Better Treatments

Given its central role in severe autism symptoms, E/I imbalance represents a promising target for therapeutic intervention. Approaches to restore balance include:

 

Pharmacological Therapies

Bumetanide

Bumetanide is a diuretic that also affects neuronal chloride homeostasis by inhibiting the NKCC1 transporter. In autism, elevated intracellular chloride levels impair the function of GABA, shifting its action from inhibitory to excitatory. Bumetanide lowers intracellular chloride, restoring GABA’s inhibitory effect and reducing hyperexcitability. Clinical trials have shown improvements in social behaviors and reduced severity of core autism symptoms in some individuals.

 

L-Type Calcium Channel Blockers

L-type calcium channels play a role in synaptic plasticity and neuronal excitability. Excessive calcium influx can contribute to hyperexcitability and oxidative stress. Blockers like nimodipine and verapamil may help stabilize neuronal activity and have shown potential in reducing seizures and hyperactivity in preclinical studies.

 

T-Type Calcium Channel Blockers

T-type calcium channels are involved in regulating burst firing and thalamocortical oscillations. Dysregulation of these channels can contribute to sensory processing abnormalities and seizures. Agents like zonisade, traditionally used for absence seizures, may also offer benefits in addressing E/I imbalances in autism.

 

Memantine

Memantine is an NMDA receptor antagonist that modulates glutamatergic signaling. By dampening excessive excitatory activity, it can reduce hyperexcitability and improve cognitive and behavioral symptoms. Clinical studies have shown mixed results, with some individuals experiencing notable benefits in areas like communication and social interactions.

 

Low-Dose Clonazepam

Clonazepam, a benzodiazepine, enhances GABAergic inhibition by increasing the activity of GABA-A receptors. At low doses, it can stabilize neural circuits without causing significant sedation. It has been used off-label to manage anxiety, hyperactivity, and seizures in autism.

 

Valproate

Valproate is an anticonvulsant and mood stabilizer that enhances GABAergic signaling and reduces excessive excitation. It has shown efficacy in managing seizures and may also improve irritability and aggression in some individuals with autism.

 

Baclofen and R-Baclofen

Baclofen is a GABA-B receptor agonist that enhances inhibitory signaling. It can modulate overactive NMDA receptor activity, which may be beneficial in cases of excitatory dysfunction. Baclofen has been studied for its role in reducing repetitive behaviors and improving social interaction in preclinical models.

 

Taurine

Taurine is an amino acid with inhibitory properties that can enhance GABAergic activity and reduce excitatory signaling. It also acts as an antioxidant, mitigating oxidative stress linked to hyperexcitability.

 

Pioglitazone

Pioglitazone, a PPAR-gamma agonist, has anti-inflammatory effects that can indirectly stabilize neural circuits by reducing neuroinflammation associated with E/I imbalances. Preliminary studies suggest it may have benefits for behavioral symptoms in autism.

Other agents including

• Anti-inflammatory Drugs: Minocycline and mefenamic acid reduce neuroinflammation, which can exacerbate E/I imbalances.
• Ion Channel Modulators: Sodium channel blockers like lamotrigine and carbamazepine stabilize hyperexcitable neurons and may reduce both seizures and behavioral dysregulation.

 

Neuromodulation Techniques

• Transcranial Magnetic Stimulation (TMS): A non-invasive method to modulate cortical excitability.
• Transcranial Direct Current Stimulation (tDCS): Targets specific brain regions to enhance or suppress neural activity.

 

 

The Role of NMDA and GABA Receptors in E/I Imbalance

Excitatory NMDA receptors and inhibitory GABA receptors play central roles in maintaining E/I balance. NMDA receptor dysfunction, characterized by either hyperactivity or hypoactivity, is implicated in autism. Overactive NMDA receptors can amplify excitatory signaling, while underactive NMDA receptors can impair synaptic plasticity. Both scenarios disrupt neural communication and contribute to autism-related symptoms.

GABA receptors, particularly GABA-A and GABA-B subtypes, are essential for inhibitory control. Dysfunctional GABAergic signaling reduces the brain’s ability to counterbalance excitation, leading to hyperexcitability.

Baclofen’s modulation of GABA-B receptors exemplifies how targeting these systems can restore balance. By reducing NMDA receptor overactivation and enhancing GABAergic inhibition, baclofen addresses multiple aspects of E/I dysregulation.

 

NMDA receptor dysfunction

Addressing NMDA receptor dysfunction requires a nuanced approach because the receptor can be either hypoactive/underactive or hyperactive/overactive in autism, depending on the individual and the specific neural circuits involved. Treatments vary based on the direction of dysfunction:

 

Treating NMDA Hypofunction

In cases where NMDA receptors are underactive, excitatory signaling is insufficient, leading to impairments in synaptic plasticity, learning, and memory. Strategies to enhance NMDA receptor activity include:

1. D-Cycloserine
• Acts as a partial agonist at the glycine site of the NMDA receptor.
• Enhances receptor activity without overactivation, making it useful for improving social and cognitive functions in some individuals with autism.
2. Sarcosine
• A glycine transport inhibitor that increases synaptic glycine levels, promoting NMDA receptor activation.
• Preclinical studies suggest potential improvements in behavioral symptoms.
3. Glycine Supplements
• Directly increase the availability of a co-agonist required for NMDA receptor activation.
• May improve signaling in circuits where glycine levels are suboptimal.

 

Treating NMDA Hyperfunction

Excessive NMDA receptor activity can lead to excitotoxicity.  When there is too much glutamate or an overactive NMDA receptor, the influx of calcium ions into the neuron becomes excessive. This causes a series of harmful processes contributing to neuronal damage, increased oxidative stress, and seizures. Strategies to dampen NMDA receptor overactivity include:

1. Memantine
• An NMDA receptor antagonist that reduces overactivation without completely shutting down receptor function.
• Clinical trials in autism have reported mixed results but some individuals benefit in areas like hyperactivity and irritability.
2. Magnesium Supplements
• Magnesium acts as a natural blocker of the NMDA receptor under resting conditions.
• Supplementation can stabilize receptor activity and reduce hyperexcitability.
3. Low-Dose Ketamine
• At sub-anesthetic doses, ketamine modulates NMDA receptor activity and enhances synaptic plasticity.
• Emerging research suggests potential benefits for specific autism symptoms, although risks and side effects must be carefully managed.
4. Antioxidants (e.g., N-Acetylcysteine, Vitamin E)
• Reduce oxidative stress caused by NMDA receptor hyperactivity.
• Support neuronal health and may mitigate excitotoxicity.

 

Balancing NMDA Dysfunction

In some cases, the same individual may show hypoactivity in some circuits and hyperactivity in others.

Combining treatments tailored to the specific functional state of NMDA receptors in different brain regions. For example, Low-dose ketamine or memantine may help dampen excessive NMDA activity in the amygdala or basal ganglia, while D-cycloserine might be used to enhance NMDA function in areas like the prefrontal cortex.

  

Calcium, Sodium and Potassium Channels

Calcium signaling is critical for excitatory neurotransmission, as calcium ions mediate glutamate release and synaptic plasticity. Dysregulated calcium channels, such as overactive L-type or T-type channels, contribute to hyperexcitability and sensory abnormalities.

Sodium channelopathies, involving mutations in genes like SCN1A, directly impact neuronal firing rates. Excessive sodium influx leads to hyperactive neurons, causing seizures and other excitatory-driven symptoms. While calcium channels influence neurotransmitter release, sodium channel dysfunction primarily affects action potential generation.

Potassium channels, responsible for repolarizing neurons after firing, also play a key role in maintaining neural stability. Mutations in potassium channel genes can prolong neuronal firing and contribute to hyperexcitability.

 

Conclusion

While E/I imbalance is not the sole cause of autism, it is a key unifying feature that connects many severe symptoms. By targeting this imbalance, clinicians can develop more precise and effective treatments tailored to the individual’s needs. Early intervention, particularly during critical periods of brain development, holds the greatest potential for improving outcomes.

As we continue to unravel the complexities of autism, the concept of E/I imbalance serves as a key nexus to understand, and more importantly, treat the challenges faced by individuals with severe autism and their families. By restoring balance, to the extent possible, both in the brain and in daily life, we can empower those with severe autism to reach their full potential. 

People with mild autism are likely affected by less extreme E/I imbalances, but they may be more aware of them. They are likely easier to treat. The principles are the same. 

The issue of sound sensitivity can affect autism from level 0 (including self-diagnosed and ADHD) all the way to level 3; it is complex because it involves both an E/I imbalance and further issues. There will be a summary post on this subject. 

 

Alpha-lactalbumin Whey Protein – Treating Neurological Dysfunction, including Epilepsy and Autism, via the Gut (Eubiosis)

 

Moo! α-Lactalbumin is a whey protein constituting 22% of the proteins in human milk and 3.5% of those in cow milk.

 

Most parents love the idea of treating their child with autism or epilepsy with diet.

Diet is so popular because you do not need a doctor - no drugs, no prescriptions, just healthy food.

This blog is about the science, which often takes us to drugs that need a prescription, but when talking about using the gut to fine-tune how the brain works, much can be achieved with nutraceuticals.

We previously saw how the ketogenic diet, which has been reducing epilepsy for one hundred years, actually works by modifying which bacteria grow in the gut.  The super high fat diet encourages specific bacteria to flourish and it is these bacteria which indirectly cause the cessation in seizures. You can replicate the effect with probiotic bacteria, without needing the highly restrictive diet at all.

Today I will introduce Alpha-lactalbumin, which is a commercially available whey protein found in mother’s milk and to a lesser extent in cow milk. 

Alpha-lactalbumin when combined with another regular in this blog, sodium butyrate, has been shown to improve autism, epilepsy and indeed depression.

The research also suggests that Alpha-lactalbumin may improve sleep and mood disorders.

  

Whey protein vs NAC

I recall reading about whey protein as an antioxidant back in 2013, when I was deciding what to try next after Bumetanide, as I developed by son's personalized polytherapy for autism. I did choose NAC, but I still recall the surprising option of whey protein.

Whey protein is popular among athletes and body builders.

Whey protein is a mixture of proteins isolated from whey, the liquid material created as a by-product of cheese production. The proteins consist of α-lactalbumin (ALAC), β-lactoglobulin, serum albumin and immunoglobulins.

 

Improved glutathione status in young adult patients with cystic fibrosis supplemented with whey protein

We sought to increase glutathione levels in stable patients with cystic fibrosis by supplementation with a whey-based protein.

 After supplementation, we observed a 46.6% increase from baseline (P<0.05) in the lymphocyte GSH levels in the supplemented group. No other changes were observed. 

Conclusion: The results show that dietary supplementation with a whey-based product can increase glutathione levels in cystic fibrosis. This nutritional approach may be useful in maintaining optimal levels of GSH and counteract the deleterious effects of oxidative stress 

 

The Antioxidant Effects of Whey Protein Peptide on Learning and Memory Improvement in Aging Mice Models

The results showed that WHP could significantly improve the accumulation of MDA and PC, increase the activities of SOD and GSH-Px, resist oxidative stress injury, and enhance the potential of endogenous antioxidant defense mechanisms. WHP can significantly improve the decline of aging-related spatial exploration, body movement, and spatial and non-spatial learning/memory ability. Its specific mechanism may be related to reducing the degeneration of hippocampal nerve cells, reducing the apoptosis of nerve cells, improving the activity of AChE, reducing the expression of inflammatory factors (TNF-α and IL-1β) in brain tissue, reducing oxidative stress injury, and improving the expression of p-CaMKⅡ and BDNF synaptic plasticity protein.

These results indicate that WHP can improve aging-related oxidative stress, as well as learning and memory impairment.

 

 

 α-lactalbumin (ALAC)

Today we are really focused on one specific whey protein, α-lactalbumin (ALAC), which is actually sold commercially as a nutraceutical.

 

https://www.arlafoodsingredients.com/health-foods/our-ingredients/alpha-lactalbumin/?downloadUrl=%252F4908eb%252Fglobalassets%252Frestricted%252F2017%252F_ho_alpha20_wellbeing_0317_v2.pdf

 

 

Applications for α-lactalbumin in human nutrition

α-Lactalbumin is a whey protein that constitutes approximately 22% of the proteins in human milk and approximately 3.5% of those in bovine milk. Within the mammary gland, α-lactalbumin plays a central role in milk production as part of the lactose synthase complex required for lactose formation, which drives milk volume. It is an important source of bioactive peptides and essential amino acids, including tryptophan, lysine, branched-chain amino acids, and sulfur-containing amino acids, all of which are crucial for infant nutrition. α-Lactalbumin contributes to infant development, and the commercial availability of α-lactalbumin allows infant formulas to be reformulated to have a reduced protein content. Likewise, because of its physical characteristics, which include water solubility and heat stability, α-lactalbumin has the potential to be added to food products as a supplemental protein. It also has potential as a nutritional supplement to support neurological function and sleep in adults, owing to its unique tryptophan content. Other components of α-lactalbumin that may have usefulness in nutritional supplements include the branched-chain amino acid leucine, which promotes protein accretion in skeletal muscle, and bioactive peptides, which possess prebiotic and antibacterial properties. This review describes the characteristics of α-lactalbumin and examines the potential applications of α-lactalbumin for human health.

 

α-Lactalbumin constitutes approximately 22% of total protein and approximately 36% of the whey proteins in human milk and approximately 3.5% of total protein and approximately 17% of whey proteins in bovine milk (Figure 1)¹,². It has an amino acid composition that is high in essential amino acids and comparatively rich in tryptophan, lysine, cysteine, and the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine.³ (Table 1)⁴. Because of its unique amino acid profile, α-lactalbumin has potential for multiple uses: (1) as a component of infant formulas, to make them more similar to breast milk; (2) as a supplement to promote gastrointestinal health or modulate neurological function, including sleep and depression; and (3) as a therapeutic agent with applications in conditions or diseases such as sarcopenia, mood disorders, seizures, and cancer. 

 

Intestinal inflammation increases convulsant activity and reduces antiepileptic drug efficacy in a mouse model of epilepsy

We studied the effects of intestinal inflammation on pentylenetetrazole (PTZ)-induced seizures in mice and the effects thereon of some antiepileptic and anti-inflammatory treatments to establish if a link may exist. The agents tested were: alpha-lactoalbumin (ALAC), a whey protein rich in tryptophan, effective in some animal models of epilepsy and on colon/intestine inflammation, valproic acid (VPA), an effective antiepileptic drug in this seizure model, mesalazine (MSZ) an effective aminosalicylate anti-inflammatory treatment against ulcerative colitis and sodium butyrate (NaB), a short chain fatty acid (SCFA) normally produced in the intestine by gut microbiota, important in maintaining gut health and reducing gut inflammation and oxidative stress. Intestinal inflammation was induced by dextran sulfate sodium (DSS) administration for 6 days. Drug treatment was started on day 3 and lasted 11 days, when seizure susceptibility to PTZ was measured along with intestinal inflammatory markers (i.e. NF-κB, Iκ-Bα, COX-2, iNOS), histological damage, disease activity index (DAI) and SCFA concentration in stools. DSS-induced colitis increased seizure susceptibility and while all treatments were able to reduce intestinal inflammation, only ALAC and NaB exhibited significant antiepileptic properties in mice with induced colitis, while they were ineffective as antiepileptics at the same doses in control mice without colitis. Interestingly, in DSS-treated mice, VPA lost part of its antiepileptic efficacy in comparison to preventing seizures in non-DSS-treated mice while MSZ remained ineffective in both groups. Our study demonstrates that reducing intestinal inflammation through ALAC or NaB administration has specific anticonvulsant effects in PTZ-treated mice. Furthermore, it appears that intestinal inflammation may reduce the antiepileptic effects of VPA, although we confirm that it decreases seizure threshold in this group. Therefore, we suggest that intestinal inflammation may represent a valid antiepileptic target which should also be considered as a participating factor to seizure incidence in susceptible patients and also could be relevant in reducing standard antiepileptic drug efficacy.

  

Increased efficacy of combining prebiotic and postbiotic in mouse models relevant to autism and depression

Highlights 

·        Prebiotic/postbiotic combination is a suitable approach in manipulating the Microbiota Gut Brain Axis. 

·        Prebiotic/postbiotic combination is more effective than single drug administration. 

·        α-lactalbumin/sodium butyrate combination improves animal behaviour in autistic (BTBR) mice. 

·        α-lactalbumin/sodium butyrate combination improves animal behaviour in the depression chronic unexpected mild stress model.

   

Conclusion

It is not by chance that mother’s milk has evolved to be rich in Alpha-lactalbumin (ALAC).

ALAC has wide-ranging health benefits. People with gut dysbiosis would seem likely to benefit from it, particularly if they have co-occurring neurological symptoms (epilepsy, ASD, depression) that are made worse by GI inflammation.

NaB (Sodium Benzoate) has some overlapping benefits with ALAC and the research shows that the combined effect is better than either alone,

The increase in production of glutathione (GSH), the body’s main antioxidant is clearly a benefit of whey protein in general and we assume its effect extends to ALAC.

NaB seems to have an effect that can be very dose dependent.  Too little has no benefit and, at least in some people, too much and you lose the benefit.

NaB is producing butyric acid and depending on your fiber intake and gut bacteria you are already producing your own butyric acid.  As a result, it makes sense that the effective dose of NaB will vary from person to person.

This continues the earlier subject of eubiosis vs dysbiosis.  The graphic below looks nice, but really is an oversimplification.  You can modify the microbiome to produce a specifically targeted change in the brain, which has nothing to do with allergic diseases.  All  very clever and a little hard to believe at first.

 

 

Source : The Role of Prebiotics and Probiotics in Prevention of Allergic Diseases in Infants

I think ALAC is an interesting choice for autism and hopefully one day there will be a clinical trial.  In that trial do not exclude those with epilepsy, but collect data of the impact of ALAC on the frequency/intensity of seizures.

 

A Deep Dive into Closely Interacting Genes/Proteins that Account for Numerous Autism/Epilepsy Syndromes – (all Calcium or Sodium ion channels)

Even I thought this post was rather a long slog, but I kept finding more and more evidence to support the basic premise, so I covered all the genes that came up for completeness.

I have been going on about the relevance of calcium channels in autism for years. I have also pointed out that while you can have severe autism for a single mutated gene, you can also “just” have a miss-expression of that same gene, without any error in the code in your DNA. You can have a little bit of that severe autism phenotype.  You can even have the opposite dysfunction, which would usually be over-expression of that gene. 

Once you have miss-expression of a gene it will cause a cascade of other effects.

This means that while you may not be able to correct the initial genetic dysfunction, you may well be able to treat what comes further down the cascade.

I like to look for associations, so I skip quickly through the research papers, but take note when I see links to things like:- 

·        Epilepsy / seizures

·        Headaches, particularly episodic

·        Mental retardation / intellectual disability

·        Mathematical ability

·        High educational attainment

·        Big Heads

·        Epilepsy / seizures

·        Pain threshold

·        Speech development (or lack thereof)

·        Sleep disturbance

·        IBD (Inflammatory Bowel Disease)

It is very easy to look up the significance of any gene.

Open the site below and just type in the name of the gene.

https://www.genecards.org/

Today’s post does touch on complex subjects, but you can happily read it on a superficial level and get the key insights.

You have about 20,000 genes in your DNA and each gene encodes a protein.  That protein could be something important like an ion channel or a transcription factor.  Today we are mainly looking at ion channels, the plumbing of the brain.

These 20,000 genes/proteins interact with each other and clever people called Bioinformaticians collect and map this data.  These maps can then show you the cascade of events that might happen if one gene/protein is miss-expressed, perhaps due to a mutation.

Today I start with 2 genes CACNB1 and CACNA1C.

CACNB1 was only recently identified as an autism gene

Genome-wide detection of tandem DNA repeats that are expanded in autism

CACNA1C is the gene that encode the calcium ion channel Cav1.2.  It is the gene behind Timothy Syndrome and the gene that I followed to Verapamil, a key part of my son’s PolyPill therapy.

The reason the gene/protein interactions are important is that the same therapy can be applied to different dysfunctional genes/proteins. A person with a genetic defect in a sodium ion channel might get a therapeutic benefit from a drug targeting a calcium ion channel.

 

The top 5 interactions with CACNA1C (in red):

 Note CACNB1 (in blue) 

There is already  lot in this blog about the calcium channel Cav1.2 (encodeded by CACNA1C).

CACNA1C is associated with Autism, schizophrenia, anorexia nervosa, obsessive-compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), Tourette syndrome, unipolar depression and bipolar disorder. 

Today we look at the “new” autism gene CACNB1. 

It is actually much more interesting that you might imagine, especially if you have to deal with epilepsy or periodic headaches at home.  You also might also have some Math Whizz back there in your family tree.

We know that brainy people, particularly mathematicians, have elevated risk of autism in their family.  Having a maths protégé in the family may not be good for your kids.

We also know that bright mathematicians are very likely to have some feature’s of Asperger’s.

The chart below expresses the top 25 interactions with the gene CACNB1 which encodes voltage-dependent L-type calcium channel subunit beta-1. It is the pink circle in the middle.

Click on the link for a higher resolution image, or on the image itself.

https://version11.string-db.org/cgi/network.pl?taskId=KBcDrcBSd4X6

 

If you look at the above chart you can spot the genes that relate to calcium channels, they start with CAC.

At the top of the chart we 6 genes starting with SCN. These genes relate to sodium ion channels.

 

SCN9A

It was interesting to me that the gene SCN9A, which encodes the ion channel Na_v1.7 is associated with insensitivity to pain.  Reduced sensitivity to pain is very common in autism.  This is a feature of Monty’s autism.

A mutation in SCN9A can also cause epilepsy. Often these seizures are fever associated.

Local anesthetics such as lidocaine, but also the anticonvulsant phenytoin, mediate their analgesic effects by non-selectively blocking voltage-gated sodium channels. Na_v1.7.

Other sodium channels involved in pain signalling are Na_v1.3, Na_v1.8, and Na_v1.9.

You would think that SCN9A would encode Nav1.9, but it seems to really be Nav1.7.  Nav1.9 is encoded by the gene SCN11A, just to see who is paying attention.

 

SCN8A

The SCN8A gene encodes the sodium ion channel Nav1.6. It is the primary voltage-gated sodium channel at the nodes of Ranvier. 

The channels are highly concentrated in sensory and motor axons in the peripheral nervous system and cluster at the nodes in the central nervous system.

If you have a mutation is in SCN8A you may face Cute syndrome.  You will have some severe challenges including treatment resistant epilepsy and may include autism and intellectual disability.

 https://www.thecutesyndrome.com/about-scn8a.html

Not such a cute syndrome.

 

SCN4A

The Na_v1.4 voltage-gated sodium channel is encoded by the SCN4A gene. Mutations in the gene are associated with hypokalemic periodic paralysis, hyperkalemic periodic paralysis, paramyotonia congenita, and potassium-aggravated myotonia.

I have covered hypokalemic periodic paralysis and hypokalemic sensory overload previously in this blog.  I showed that I could reduce Monty’s sensitivity to the sound of a baby crying by giving a modest potassium supplement. 

Mutations in SCN4A are also associated with abnormal height and abnormalities of the head, mouth or neck.

 

SCN3A

The Na_v1.3 voltage-gated sodium channel is encoded by the SCN3A gene

It has recently been shown that speech development is affected by this ion channel.  Many people with severe autism never fully develop speech.

  

Sodium channel SCN3A (Na_V1.3) regulation of human cerebral cortical folding and oral motor development

Channelopathies are disorders caused by abnormal ion channel function in differentiated excitable tissues. We discovered a unique neurodevelopmental channelopathy resulting from pathogenic variants in SCN3A, a gene encoding the voltage-gated sodium channel Na_V1.3. Pathogenic Na_V1.3 channels showed altered biophysical properties including increased persistent current. Remarkably, affected individuals showed disrupted folding (polymicrogyria) of the perisylvian cortex of the brain but did not typically exhibit epilepsy; they presented with prominent speech and oral motor dysfunction, implicating SCN3A in prenatal development of human cortical language areas. The development of this disorder parallels SCN3A expression, which we observed to be highest early in fetal cortical development in progenitor cells of the outer subventricular zone and cortical plate neurons and decreased postnatally, when SCN1A (Na_V1.1) expression increased. Disrupted cerebral cortical folding and neuronal migration were recapitulated in ferrets expressing the mutant channel, underscoring the unexpected role of SCN3A in progenitor cells and migrating neurons.

 

 SCN2A

The Na_v1.2 sodium ion channel is encoded by the SCN2A gene.

Mutations in this gene have been implicated in cases of autism, infantile spasms bitemporal glucose hypometabolism, and bipolar disorder and epilepsy.

  

SCN1A

 The Na_v1.1 sodium ion channel is encoded by the SCN1A gene.

Mutations to the SCN1A gene most often results in different forms of seizure disorders, the most common forms of seizure disorders are Dravet Syndrome (DS), Intractable childhood epilepsy with generalized tonic-clonic seizures (ICEGTC), and severe myoclonic epilepsy borderline (SMEB).

Mutations are also associate with

·        Febrile seizures up to 6 years of age

·        MMR-related febrile seizures

·        Sleep duration

·        Educational attainment

 

 

Now the Calcium ion channels:-

CACNB1

The gene CACNB1 encodes the Voltage-dependent L-type calcium channel subunit beta-1.

CACNB1 regulates the activity of L-type calcium channels that contain CACNA1A, CACNA1C or CACNA1B.  Required for functional expression L-type calcium channels that contain CACNA1D.

The gene is associated with headaches, asthma, mathematical ability and acute myeloid leukemia

CACNB2

The gene CACNB2 encodes the Voltage-dependent L-type calcium channel subunit beta-2.

Mutation in the CACNB2 gene are associated with Brugada syndrome, autism, attention deficit-hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder, and schizophrenia.

 

CACNB3

The gene CACNB3 encodes the Voltage-dependent L-type calcium channel subunit beta-3.

Diseases associated with CACNB3 include Headache and Lambert-Eaton Myasthenic Syndrome.

Lambert–Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder characterized by muscle weakness of the limbs.

CACNA1A

The Ca_v2.1 P/Q voltage-dependent calcium channel is encoded by the CACNA1A gene.

Mutations in this gene are associated with multiple neurologic disorders, many of which are episodic, such as familial hemiplegic migraine, movement disorders such as episodic ataxia, and epilepsy with multiple seizure types.

 

CACNA1B

The voltage-dependent N-type calcium channel subunit alpha-1B is encoded by the CACNA1B gene. Diseases associated with CACNA1B include Neurodevelopmental Disorder With Seizures And Nonepileptic Hyperkinetic Movements and Undetermined Early-Onset Epileptic Encephalopathy.

 

CACNA1C (covered earlier in this blog)

The CACNA1C gene encodes the calcium channel Ca_v1.2.   Ca_v1.2 is a subunit of the L-type voltage-dependent calcium channel.

 

CACNA1S

The CACNA1S gene encodes Ca_v1.1 also known as the calcium channel, voltage-dependent, L type, alpha 1S subunit.

This gene encodes one of the five subunits of the slowly inactivating L-type voltage-dependent calcium channel in skeletal muscle cells. Mutations in this gene have been associated with hypokalemic periodic paralysis, thyrotoxic periodic paralysis and malignant hyperthermia susceptibility.

Mutations are associated with inflammatory bowel disease (IBD) and ulcerative colitis.

Note that Rezular or R-Verapamil was a drug developed to treat IBD.

 

CACNA1D

The CACNA1D gene encodes Ca_v1.3.

Ca_v1.3 is required for proper hearing.

Some mutations in CACNA1D) cause excessive aldosterone production in aldosterone-producing adenomas (APA) resulting in primary aldosteronism, which causes treatment - resistant arterial hypertension. These mutations allow increased Ca²⁺ influx through Cav1.3, which in turn triggers Ca²⁺ - dependent aldosterone production. The number of validated APA mutations is constantly growing. In rare cases, APA mutations have also been found as germline mutations in individuals with neurodevelopmental disorders of different severity, including autism spectrum disorder.

Recent evidence suggests that L-type Ca_v1.3 Ca²⁺ channels contribute to the death of dopaminergic neurones in patients with Parkinson's disease

Inhibition of L-type channels, in particular Ca_v1.3 is protective against the pathogenesis of Parkinson's in some animal models

CACNA1D is highly expressed in prostate cancers compared with benign prostate tissues. Blocking L-type channels or knocking down gene expression of CACNA1D significantly suppressed cell-growth in prostate cancer cells

 

CACNA1E

CACNA1E encodes the calcium channel Cav_2.3 , also known as the calcium channel, voltage-dependent, R type, alpha 1E subunit.

These channels mediate the entry of calcium ions into excitable cells, and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death.

Mutations are associated with epilepsy, acute myeloid leukemia, mathematical ability and having a big head.

 

CACNA1F

The gene CACNA1F encodes Ca_v1.4.

Mutations in this gene can cause X-linked eye disorders, including congenital stationary night blindness type 2A, cone-rod dystropy, and Aland Island eye disease

Mutations are associated with astigmatism and other eye conditions.

 

CACNA2D1

The CACNA2D1 gene encodes the voltage-dependent calcium channel subunit alpha-2/delta-1.

Alpha2/delta proteins are believed to be the molecular target of the gabapentinoids gabapentin and pregabalin, which are used to treat epilepsy and neuropathic pain. 

Genomic aberrations of the CACNA2D1 gene in three patients with epilepsy and intellectual disability

CACNA2D2

The CACNA2D2 gene encodes the voltage-dependent calcium channel subunit alpha2delta-2 is a protein that in humans is encoded by.

The Calcium Channel Subunit Alpha2delta2 Suppresses Axon Regeneration in the Adult CNS

CACNA2D3

The CACNA2D3 gene encodes the Calcium channel alpha2/delta subunit 3.

Cacna2d3 has been associated with CNS disorders including autism.

Synaptic, transcriptional and chromatin genes disrupted in autism

CACNA2D4

Calcium channel, voltage-dependent, alpha 2/delta subunit 4 is a protein that is encoded by the CACNA2D4 gene.

Mutations in CACNA2D4 are associated with mathematical ability and educational attainment.

 

CACHD1

CACHD1 (Cache Domain Containing 1) is not well researched, it may regulate voltage-dependent calcium channels.  It is moderately associated with anxiety.

 

CACNG1

The CACNG1 gene encodes the Voltage-dependent calcium channel gamma-1 subunit

Diseases associated with CACNG1 include hypokalemic periodic paralysis, type 1 and Malignant Hyperthermia.

 

REM1

The protein encoded by this gene is a GTPase and member of the RAS-like GTP-binding protein family. The encoded protein is expressed in endothelial cells, where it promotes reorganization of the actin cytoskeleton and morphological changes in the cells.

Recall my posts about RASopathies and MR/ID.

Diseases associated with REM1 include Mental Retardation and late onset Parkinson’s disease.

 

NALCN

NALCN (Sodium Leak Channel, Non-Selective) gene encodes a voltage-independent, nonselective cation channel which belongs to a family of voltage-gated sodium and calcium channels that regulates the resting membrane potential and excitability of neurons.

It is highly associated with an abnormality in the process of focusing of light by the eye in order to produce a sharp image on the retina.

It is associated with mental or behavioral disorders and unusual body height.

 

GEM

GEM encodes a protein that belongs to the RAD/GEM family of GTP-binding proteins.

It is associated with heart disease.

 

Conclusion

I was really surprised just how many autism/epilepsy genes are so closely related to the newly recognised autism gene CACNB1.

I hope you can see that a child without a mutation in CACNB1 can be affected by several of today's genes.  What matters is differentially expressed genes (DEGS).

In my simplification of autism, I have a category called channelopathies and differentially expressed genes (DEGS).  I did add the DEG part a while back, but this chart has stood the test of time.

I think many people with severe autism are affected by the genes in today’s post.

Headaches and epilepsy are an integral part of autism and better not considered as comorbidities. The same is true with big/small heads and indeed high/low IQ.

 

If you do invest in genetic testing, you would be well advised to look up any affected genes yourself. From what I have seen, do not rely on your DAN Doctor to do this thoroughly.