Israel screening Ashkenazi Jews for the TBCB gene that can cause autism

 

Albert Einstein – perhaps an Aspie, but not a TBCB autistic

Today’s post was prompted by a very matter of fact approach proposed to deal with autism caused when both mother and father carry a single mutation in the TBCB gene. The unaffected parents produce a child with a 25% chance of having autism and a very specific movement disorder because the child has mutations in both of its copies of the gene.

The TBCB gene helps make something called tubulin, which is one of the three main components of the cytoskeleton.

The cytoskeleton plays a role in many well-known neurodegenerative disorders such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis (ALS).

Disruptions in tubulin's normal function can impair cellular processes, including those involved in neuronal signaling and motor control, contributing to movement disorders. So we should not be surprised that one feature of TBCB autism is a difficulty in learning how to walk

 

Israeli researchers discover gene mutation in Ashkenazi Jews that can cause autism

In non-Jewish populations, the occurrence of the mutation in TBCB is 5 in 100,000.

In Ashkenazi Jews, the rate is 1 in 80.

The Israeli Health Ministry incorporated a screening test for the TBCB gene mutation as part of the national healthcare basket in November, making it accessible to all couples planning for pregnancy.

As reported in the Times of Israel, the parents’ options proposed are: 

“They can choose to have an abortion, she said, or to have in-vitro fertilization with genetic screening, in which only embryos without two abnormal copies of the TBCB gene are put into the uterus.

The third option is to keep the pregnancy, she said.

A year after the child is born, she said, parents will be able to see if their child has difficulty with motor development.

In that case, “they can give the child physiotherapy at an early age and help them develop,” Bratman-Morag said.

The illness “causes them difficulties with walking, but they can learn to live with that,” she said.

I don’t think you could be quite so blunt in other countries. The autism self-advocates would go bananas. Their worst dreams have actually materialized – "eugenics" has arrived and in Israel of all places.

The IVF therapy suggested is a very pragmatic approach. I am really surprised they propose it.

The arguments are similar to those that surround Down syndrome. In the world’s most advanced countries, like Denmark and Iceland, almost all DS fetuses are aborted.  In the US the number of live births actually went up, according to the chart below.

The difference with TBCB is that you can test the parents before conception and not just the fetus.

Source https://downsyndroom.nl/wp-content/uploads/2022/09/down-syndrome-population-usa-factsheet.pdf

The downside of Endogamy

Many genes are tagged as being associated with higher IQ, or higher educational attainment and some of these are also linked to autism.

Like it or not, some groups of people are cleverer than others, Albert Einstein might have been at the extreme for Ashkenazi Jews, but he comes from a clever genetic group. These discrete genetic groups are created by what is politely referred to as endogamy (marrying within the community), biologically it is interbreeding.

Unfortunately, there are also downsides caused by centuries of interbreeding particularly within a group that started out relatively small. European royal families famously suffered from it; in their quest for political alliances they created very unhealthy bloodlines.  The Habsburg dynasty took marrying their cousins to an extreme in their quest to keep territory and wealth in the family. This led to infertility, intellectual disability, physical disability, reduced lifespan and the famous Habsburg pronounced lower jaw. For American readers, this family were the royalty in Austria-Hungary, Spain, Holy Roman Empire (Germany etc), Belgium, Luxembourg, Netherlands etc. Very briefly a Habsburg, Maximilian I, was Emperor of Mexico - he was executed by firing squad in 1867.

Ashkenazi Jews are descended from communities that lived in Central and Eastern Europe in the middle ages. The majority now live in the United States. Of 11 million people, 6 million live in the United States. In the world there are another 5 million non-Ashkenazi Jews. In Israel there are 7 million Jewish people and the largest group is Mizrahi, who are descended from the Middle East and North Africa.

For Ashkenazi Jews the following medical conditions are known to be over represented:

• Bloom syndrome
• Canavan disease
• Cystic fibrosis
• Dihydrolipoamide dehydrogenase deficiency
• Familial dysautonomia
• Familial hyperinsulinism
• Fanconi anemia type C
• Gaucher disease
• Glycogen storage disease type 1A
• Joubert syndrome
• Maple syrup urine disease
• Mucolipidosis type IV
• Nemaline myopathy
• Niemann-Pick disease type A
• Spinal muscular atrophy
• Tay-Sachs disease
• Usher syndrome type 1F
• Usher syndrome type III
• Walker-Warburg syndrome

Four cancer genes are known to cause problems

• BRCA1 and BRCA2, linked to
• Breast cancer and ovarian cancer in women
• Breast cancer and prostate cancer in men
• Melanoma
• Pancreatic cancer
• About one in every 40 Ashkenazim has a BRCA mutation; in the general population, the rate is about one in every 400 people.
• GREM1, linked to colon cancer
• APC, linked to colon cancer

This is a wealthy group of people living in a country that looks after the health of rich people very well. That must be the reason why the group has been so well studied. I was a little surprised.

The recent research in Israel has identified the TBCB gene to be an autism gene and that mutations are substantially more come in Ashkenazi Jews.

The mutation is not more common in the other Jewish ethic groups (Sephardi, Mizrahi, Ethiopian, Yemenite, Bukharan, Indian, Kavkazi, Karaite, Cochin, Kaifeng).

Conclusion

I was a little surprised to learn recently from a chat with a kindergarten teacher who worked in Qatar that many of the kids already knew who they were going to marry. “He’s my cousin and I am going to marry him when I grow up,” said the little girl. This kind of arranged marriage is still common there. Well the Habsburgs also did it, so a European can hardly judge them.

Consanguineous marriage (cousin marriage) is alive and well.

Mixing up the gene pool looks to me like the best way to go.

In ancient times forced mixing was common. The Vikings used to abduct young women on the raiding trips across Europe, this continued until the Christianization of Scandinavia between the 9^th and 12^th centuries. In the wilder parts of the Balkans there was a practise called otmitza up until the 1800s, which can be best described as bride kidnapping, where the bride would be brought from a distant community over the mountains. In parts of Central Asia the practise of ala kachuu (to take and flee) continues to this day. In Kyrgyzstan 14% percent of married women say they were kidnapped. The UNDP have a special program to try and stop it.

When it comes to reducing neurodevelopmental disorders mixing up the gene pool looks the best option. Modern technology risks taking society in the opposite direction with online dating apps matching Aspie girl with Aspie boy to then potentially produce a more severe kind of autism, but then their bloodlines end. Mother Nature can indeed be harsh.

I wonder what will be the next genetic test for autism to join Israel’s “national healthcare basket.” Some people will like the idea and others will not, but it looks like the future is already here.