Jewish Genetic Diseases - Why?

Rappel

Fri, Dec 14 2018, 6:21 am

daagahminayin wrote:

Right, so I guess you’ve clarified my basic hashkafic question: our small gene pool comes from not marrying out. Why did Hashem set it up that we would get this negative consequence from following halacha?

Hashkafically?

Obviously we can't know for sure, but I think it's in order to reunite the Jewish people.

For upward of a thousand years, Jewish groups were completely genetically separated by galut.

Now that we are in the early stages of geulah, it's time to reunite with all our brethren - and marrying outside our genetic gene pool is roughly akin to marrying outside our hashkafic pool of Ashkenazic/Mizrachi/Sephardic traditions.

We're remixing the Jewish people into a unified whole.

happyone

Fri, Dec 14 2018, 7:45 am

there arent more Jewish genetic illnesses. fact is Jews are more likely to marry spouses that have similar genes and come from the same place. Jews have more children so that increases chances. Have a conversation with geneticists and youll see thats not accurate. I can name loads of genetic illnesses specific to african americans, common among non jews and specific to certain nationalities. sickle cell, muscular dystrophy, hemophilia, cystic fibrosis, leukodystrophy and many metabolic diseases are far more common in non jews than you think!

FranticFrummie

Fri, Dec 14 2018, 7:52 am

Rappel wrote:

You took my answer! You said it really well, though. Great minds think alike. Wink

imasoftov

Fri, Dec 14 2018, 8:07 am

happyone wrote:

The list doesn't answer the question. How prevalent are those diseases and in which populations?

A moshol: Rivka has apples, Timna has oranges and pears. Who has more pieces of fruit?
Answer: it is impossible to tell from the information provided. Even if we should learn that Timna also has lemons and bananas.

For that matter, what's the right thing to measure? I suppose one would be the chance per birth. Another might be number of affected births per million, yet another might be total number of births. And these differ becaue of different population sizes and birth rates. And then do we go by the general Jewish birthrate or the frum birthrate? For that matter I wonder if rates of genetic disorders varies, some of us (and I'm not saying this has anything to do with frumkeit) must be more genetically diverse than others. Maybe that would be an interesting poll, although I don't know what poll question to ask to measure that? I have no idea myself. OK, I know where my grandparents are from, but they're all countries with changing borders, and people moved around, also people left one country for another to marry first cousins who lived in the second, so forget the poll. That my father is Lithuanian and German, maybe his parents were still closely related, while my mother's two Polish parents could have been more distantly related than two humans randomly selected from anywhere on Earth ...

imasoftov

Fri, Dec 14 2018, 8:34 am

amother wrote:

This has nothing to do with "why do bad things happen to good people" nor is it a punishment from hashem.
It's the result of the choices people made. They married their cousins.

If a woman married her brother and they have kids and the kids are sick... Is that a punishment from hashem or is that just an outcome from incest?

We need to stop blaming hashem.. he created loads of Jews. Of ashkenazim married Sephardic Jews .. the gen pool would be bigger

Except marriages between cousins (or more distantly related people who happen to have the same defective gene) aren't prohibited and marriage between siblings is.

amother

Lawngreen

Fri, Dec 14 2018, 9:06 am

imasoftov wrote:

It's easy to criticize them with what we know today, but did our ancestors who interbred know this?

Of course not, and no one is criticizing them. We're just answering the question why we have so many genetic diseases among us.

Dor Yeshorim was created for a reason. We do have a higher than average genetic disease rate.

Of course that doesn't answer the Hashkafa part of this. Our ancestors who interbred didn't know the result of it, but now that we do, what does it mean for us? Perhaps, it means that we shouldn't be creating our own little circles, and living only in that world. We should reach out to all Jews, across all borders, and try to unify and unite ourselves.

Fri, Dec 14 2018, 9:25 am

daagahminayin wrote:

Pre-question: Does this mean that Ashkenazi Jews have higher numbers of genetic diseases than the general population, or not because each ethnic group has its own common genetic diseases?

Good question. A quick Google search reveals no answer. Before getting embroiled in a hashkafic debate, let's hear from a real geneticist, if there is one on Imamother. Otherwise, we're just patting ourselves on the back for being more special than everyone else, and this may not be a good example of Jewish distinctiveness.

TranquilityAndPeace

Fri, Dec 14 2018, 9:37 am

Amarante wrote:

Ashkanazi also represent a statiscally small genetic pool.

Almost every Ashkanazi Jew is a third or fourth cousin. Therefore recessive genes are more likely to be carried by potential mates than if people married in a larger population group.

What? I know many of my 3rd and 4th cousins. I just went to my 3rd cousins's bar mitzvah.

I would guess it's more like 7th cousins and beyond. I know my family tree 6 generations back on both sides as does my husband, and probably many others. Unfortunately, many were killed in WWII which limited the amount of cousins that could have been.

daagahminayin

Fri, Dec 14 2018, 9:56 am

Rappel wrote:

Now that we are in the early stages of geulah, it's time to reunite with all our brethren - and marrying outside our genetic gene pool is roughly akin to marrying outside our hashkafic pool of Ashkenazic/Mizrachi/Sephardic traditions.

We're remixing the Jewish people into a unified whole.

I love this answer and also Whatfor’s on the previous page who mentioned welcoming the ger.

Of course we can never know for sure answers to this type of question, but I do find it worthwhile to think about and see what we can come up with - to see if there is a moral that jives with our other present day Torah values.

And I think this answer fits the bill: the notion that while we have a mandate to marry within the Jewish people to preserve our mesorah, too much sameness is damaging, and we benefit from seeking out and integrating diversity into our gene pool.

The same could be said for ideas.

Notsobusy

Fri, Dec 14 2018, 10:07 am

amother wrote:

I think the reason why we have dor yeshorim is because we are a relatively small community and we are all more connected to each other and to our extended families than the non Jewish population. It's much more likely that someone in our community who has a baby with a rare genetic disease will know someone who knows someone who also has such a baby. So it was easy to pinpoint which genetic diseases were a threat to our community and develop the tests for those specific genetic diseases.

Laiya

Fri, Dec 14 2018, 10:58 am

TranquilityAndPeace wrote:

We are not all 3rd or 4th cousins, but we are descendants of people who were each likely related to their relatives in multiple ways. This magnifies the effect of how close a relationship would appear, genetically, when there is a connection.

So you and I might be 8th cousins, but on 4 different branches of our families, which would make it appear that we are 3rd or 4th cousins.

amother

Pumpkin

Fri, Dec 14 2018, 11:11 am

amother wrote:

Look, aside from genetic diseases, there are plenty of awful horrible deathly occurrences that happen to completely innocent people including babies. I'm not saying to "blame hashem" but let's not pretend as if all the awful horrible things that happen in this world are a result of bad or selfish decisions made by us flawed humans. That's just a silly premise. As far as the reason hashem brings tragedy to the innocent nobody knows, but let's not pretend that this is all preventable had we made different decisions. Nonsense.

Amarante

Fri, Dec 14 2018, 11:21 am

TranquilityAndPeace wrote:

I signed up for ancestry.com and wound up with literally pages and pages of third and fourth cousins. When I googled for information about genealogy and Ashkenazi Jews, the explanation was that there was so much endogamy over an extended period of time that Ashkenazi Jews share genetic material with other Ashkenazi Jews in a manner that is unlike other modern population groups.

Here is the Wiki entry on Ashkenazi ancestry - that is an incredibly small gene pool from a relatively short period of time.

Today's 10 million Ashkenazi Jews descend from a population of only 350 individuals who lived about 600–800 years ago.[15] That population derived from both Europe and the Middle East. There is evidence that the population bottleneck may have allowed deleterious alleles to become more prevalent in the population due to genetic drift.[16] As a result, this group has been particularly intensively studied, so many mutations have been identified as common in Ashkenazim.[17] Of these diseases, many also occur in other Jewish groups and in non-Jewish populations, although the specific mutation which causes the disease may vary between populations. For example, two different mutations in the glucocerebrosidase gene causes Gaucher's disease in Ashkenazim, which is their most common genetic disease, but only one of these mutations is found in non-Jewish groups.[4] A few diseases are unique to this group; for example, familial dysautonomia is almost unknown in other populations.[4]

https://en.wikipedia.org/wiki/....._Jews

ETA - And because of the relatively "purity" of the gene pool Ashkenazi Jews makes excellent subjects for genetic research. Also, we tend to be located near large metropolitan areas which is where the studies are being conducted. I might be wrong but isn't Israel a major center of genetic research - chicken or egg in terms of there being a vested interest in genetic research.

I don't think it's because Ashkenazi have more genetic diseases or the potential for same - it's just that because of the intermarriage among a small population group, it is much more likely that two carriers of recessive genes will marry. In the larger population it would be less likely that two carriers of a recessive gene would marry which is why Ashkenazi Jews are tested for Tay Sachs whereas most people in the larger population are not routinely tested for genetic disorders before marrying.

Last edited by Amarante on Fri, Dec 14 2018, 11:27 am; edited 1 time in total

amother

Fuchsia

Fri, Dec 14 2018, 11:24 am

I'm a giyores with a Jewish father. As a convert, I imagined that I didn't need to do Dor Yesharim. I got married and had kids. One of them is affected by a very rare and serious "Jewish" genetic condition. It's not entirely accurate to call it a "Jewish disease", as it can be found in all populations, but carriers of the mutations that cause the disease are about twice as frequent in the Jewish population than they are in the non-Jewish population.

When we discussed our child's genetic test results with her doctor, she asked if my husband and I are related! Not only did our child end up with this recessive genetic condition, but, out of a huge number of possible mutations that could have caused this specific disease, our child had the same mutation from both her parents. This is relatively rare and indicates parents from a common ancestor, although at this point it's impossible to say how far back we'd have to go to find that common ancestor. It's interesting, because the mutation isn't the most common Ashkenazi "founder" mutation. Still, it seems likely that it comes from our shared Eastern European Jewish ancestry. Either that or we are just incredibly "lucky."

Notsobusy wrote:

But isn't the reason we are "more connected to each other" because we in-marry (inbreed)? There are plenty of non-Jewish communities that have very strong family ties across generations.

My personal theory as to why Jewish diseases are more well known and studied is because of the disproportionate achievements of Jewish scientists and researchers. Jews are more highly represented in certain fields, such as the sciences, technology, law, business, and politics. There are a number of theories as to why this is so, but that is beside the point. A scientist or researcher is more likely to choose a topic of research that is personally relevant. For example, a Jewish medical researcher or doctor who has a history of Tay-Sachs in his family might be likely to choose that disease as a subject of research. Likewise, researchers from a particular ethnic background are more likely to have personal connections that would make studying that population more accessible than studying a unrelated population.