Turner Syndrome, Estradiol and Autism-lessons from the X Chromosome

This post is best read if you have reviewed the earlier ones regarding the estradiol/testosterone disturbances in autism and how they govern the RORα “switch” that then triggers a torrent of other dysfunctions. So the hormonal disturbance, if present, is a key point at which to make a potent intervention. 

The Purkinje-RORa-Estradiol-Neuroligin-KCC2 axis in Autism 

Beauty is in the eye of the beholder

In the mass media it is now popular to dismiss the fact that autism is far more prevalent on boys than girls. In the scientific literature, fortunately, they stick to the facts and much is written about the sex differences in autism.

As we have seen in earlier posts, females have some natural defences against autism. They have two X chromosomes and of course they have those all-important neuroprotective female hormones (estrogen/estradiol, progesterone etc.). In effect, the more female you are, the more protection you have against idiopathic autism and any X-chromosome linked single gene autism. So a girl with Fragile-X syndrome is likely to be far less affected than her brother with same condition.
Recall that we all have 23 pairs of chromosomes and that the 23^rd set contains two Xs in girls and in boys one X and one Y. The girls’ “spare” X chromosome is also what gives them their feminine features.  

It is interesting to look what happens to females who lack part of their second set of X- chromosomes. This diagnosis is called Turner Syndrome. As you might have guessed people with Turner Syndrome have much lower levels of female hormones and a higher incidence of autism, although some people find this controversial. The autism-like characteristics of TS include:-

·      Impairments in social functioning

·      Impairments in face and emotion processing

·      Spatial executive deficits

·      Poor social coping skills and increased immaturity

·      Hyperactivity and impulsivity

Turner syndrome occurs in 50 per 100,000 live-born females. Autism occurs about ten times for frequently, so about 500 per 100,000 live-born females.  Turner syndrome provides the extreme case of what happens when females have too little estrogen/estradiol.

I think you will find a large group of females with idiopathic autism (no identified genetic defects) have/had low levels of estradiol. I think this is the reason that facial recognition studies show that some females with idiopathic autism look different, (as do many boys, of course). We already know that most single gene types of autism produce tell-tale signs, often on the face (big ears, wide face, big/small head etc).

I am not suggesting that there is anything wrong with looking different; rather it may be a useful diagnostic tool and not an expensive or invasive one. Physical variation has long been used to identify genetic syndromes, before genetic testing became widely available.

Physical variation inside your head

We saw in an earlier post that MRI scans of the autistic brains actually do often show subtle differences, particularly when you use software to read them, rather than the naked eye. Traditionally doctors say that MRIs are “normal” in autism and cannot be used to diagnose it. Yet in a recent studies machine reading of MRIs was able to identify 70%-96% of autism cases.  Some of these are scans taken before birth.

This is interesting, because ultimately you might bypass the current very slow and subjective observational diagnosis process.

Brain imaging studies seek signs of autism before birth

Infant MRIs show autism linked to increased cerebrospinal fluid

MRIs show a brain anomaly in nearly 70 percent of babies at high risk of developing the condition who go on to be diagnosed, laying the groundwork for a predictive aid for pediatricians and the search for a potential treatment

Functional neuroimaging of high-risk 6-month-old infants predicts a diagnosis of autism at 24 months of age

Predicting the future with brain imaging

In a new study, Emerson et al. show that brain function in infancy can be used to accurately predict which high-risk infants will later receive an autism diagnosis. Using machine learning techniques that identify patterns in the brain’s functional connections, Emerson and colleagues were able to predict with greater than 96% accuracy whether a 6-month-old infant would develop autism at 24 months of age. These findings must be replicated, but they represent an important step toward the early identification of individuals with autism before its characteristic symptoms develop.

A Breakthrough AI Can Now Predict Which Babies Will Develop Autism

MRI scanners are very widely used, but you do have to keep very still inside when they are in operation. The even harder part is the reading of the data. It is clear that some standardized machine reading (A/I artificial intelligence) process is required to notice every possible variation. You could have a centralized location where you just submit your MRI data, the center gets to keep the data and learn from it; and you get their insight as to what differences there might be.

Facial Differences vs MRI Brain Differences

I like to keep things simple and under my control.  In the short term we have to settle for facial differences, since any well-managed MRI process will be decades away.

Hormonal Variation in Autism

Hormonal differences were one of the key areas I identified years ago in this blog. Big/small heads result from disturbances in pro-growth signalling pathways. We should expect variations in bone-age, early/late onset of puberty and indeed big variations in height and weight.

In Turner Syndrome, the girls tend to be very short and they are often treated with growth hormones, as well as female/feminizing hormones.  

Great caution has to be taken when treating children with any hormones. When children are treated, it is for serious reasons like not achieving puberty, or having a serious growth delay (being very short).

Hormone Therapy During Pregnancy

In some countries hormones are given during pregnancy although I think this would be seen as odd/risky in some advanced countries.

We have already seen that couples who have difficulty producing a child often have a family history that includes autism. It was proposed by one serious fertility expert that what helps prevent miscarriage also helps prevent autism. This did sound odd when I first read about, but when you look in more depth there is a basis for this idea.

That expert has these two websites:-

http://www.preventautism.com/

http://www.preventmiscarriage.com/

Progesterone supplements have been recommended for more than 50 years for women struggling with infertility, but research now shows they can also help prevent miscarriage.

Luteal start vaginal micronized progesterone improves pregnancy success in women with recurrent pregnancy loss

Tamoxifen, an estrogen receptor (ER) antagonist, is also used to treat infertility.

Estradiol is sometimes prescribed during pregnancy.

Testosterone is produced naturally during pregnancy.

All this is clearly beyond the scope of this blog, but perhaps altered female/male hormones during pregnancy might be a biomarker of some future autism and female hormones might be a protective therapy in the subgroup of pregnant mothers with low levels of these hormones and/or high levels of testosterone. Recall that human trials in the hospital ER have shown certain substances are highly neuroprotective (progesterone, atorvastatin etc) and when administered immediately after a traumatic brain injury markedly improve the outcome.                                         

Hormone Therapy for Autism

Hormone therapy in people with autism would be controversial, but we saw in an earlier post that via RORα the balance between testosterone and estradiol affects numerous biological relevant to autism.

Many pictures of girls/women with autism, that you can view online, suggest reduced levels of estradiol. Faces look more boy-like. Many males with autism are reported to have physical features of high testosterone and low estradiol. 

One example of many:-

https://www.npr.org/2017/11/28/566788182/navigating-life-on-campus-when-youre-on-the-autism-spectrum

Both faces in the above article show clear indications of autism. Since both young people do have autism, this should not surprise anyone.

My own conclusion is that if you have autism or Asperger’s, a little extra estradiol could therapeutic, particularly if you have physical features that reinforce this.

There are of course many males and females with autism who are physically indistinguishable from the rest of the world. The point of this post is to highlight that visible differences may help to define the sub-type of autism and indicate possibly effective therapies, that exist today.

Obesity and Estradiol

In an earlier post on estradiol, I pointed out that in males estradiol is made in your adipose (fat) tissue. In the US many people with autism are overweight, in part due to side effects from their likely un-needed psychiatric medications; this has the hidden benefit of increasing their estradiol levels, feminizing their behavior slightly and shifting RORalpha in the right direction.

This also means that losing weight should be helpful to obese females with estrogen receptor positive breast cancer.  Research does support this.

Asperger’s and too much Estradiol?

We saw in earlier posts that much autism is associated with reduced expression of estrogen receptor beta and low aromatase, so high testosterone and low estradiol.

We have seen on many occasions that when one extreme exists in autism, so usually does the other; so many big heads, but also some tiny ones, NMDAR hypofunction, but also hyperfunction.

There was a lot of talk a while back in the media about children undergoing therapy to change their gender, and it was highlighted that Asperger’s was much over-represented in this group. One expert got into trouble for suggesting that their autism was causing them to obsess about their identity and so mistakenly convince a boy that he would rather be a girl.  It seems that these days some clinicians are then all too willing to provide drug therapy and then operate on them, to make them female.  I do wonder if perhaps some of these boys with Asperger’s might have the other extreme of aromatise. That would give them too little testosterone and too much Estradiol.

I think measuring these hormones is quite a good idea, as I keep repeating, they go on to affect the critical “switch”  RORα, which then impacts a large number of biological processes implicated in autism.  In other words you can try to normalize a wide range of important autism variables, just be tweaking RORα, via estradiol/testosterone.

A boy with high testosterone, and so low estradiol, will likely exhibit physical signs of this, just like the girl with low estradiol. These are just pieces of the puzzle, in plain view, that can be used to understand each specific case of autism. And no machine reading of an MRI is required.

For those left wanting more:

A very thorough paper on Turner Syndrome:-

Turner Syndrome

Turner syndrome (TS) is a neurogenetic disorder characterized by partial or complete monosomy-X. TS is associated with certain physical and medical features including estrogen deficiency, short stature and increased risk for several diseases with cardiac conditions being among the most serious. Girls with TS are typically treated with growth hormone and estrogen replacement therapies to address short stature and estrogen deficiency. The cognitive-behavioral phenotype associated with TS includes strengths in verbal domains with impairments in visual-spatial, executive function and emotion processing. Genetic analyses have identified the short stature homeobox (SHOX) gene as being a candidate gene for short stature and other skeletal abnormalities associated with TS but currently the gene or genes associated with cognitive impairments remain unknown. However, significant progress has been made in describing neurodevelopmental and neurobiologic factors underlying these impairments and potential interventions are on the horizon

Estradiol levels in girls with Turner's syndrome compared to normal prepubertal girls as determined by an ultrasensitive assay.

We utilized an ultrasensitive assay to study estradiol levels in 34 girls with TS and 34 normal age-matched prepubertal girls between the ages of 5 and 12 years. The average estradiol level in the girls with TS (6.4 +/- 4.9 pmol/l estradiol equivalents) was significantly lower than in the normal prepubertal girls (12.7 +/- 10.8 pmol/l estradiol equivalents; p < 0.01). Girls with TS were significantly shorter, and weighed less than the normal prepubertal girls, as expected. The estradiol level was not significantly correlated with height, bone age, 

Facial features provide clue to autism severity