web analytics
September 23, 2014 / 28 Elul, 5774
At a Glance
Sections
Sponsored Post
Meir Panim with Soldiers 5774 Roundup: Year of Relief and Service for Israel’s Needy

Meir Panim implements programs that serve Israel’s neediest populations with respect and dignity. Meir Panim also coordinated care packages for families in the South during the Gaza War.



Broader Lessons from Genetic Studies of the Ashkenazi Jewish Population


This year marks the 80th anniversary of the influential paper published by a Mount Sinai physician, Dr. Burrill Crohn, and his colleagues that for the first time characterized a disease associated with severe inflammation of the intestine. Patients with what was later named Crohn’s disease develop diarrhea, fever, stomach pain, and often lose weight. Crohn’s is now classified as an autoimmune condition in which the immune system attacks its own healthy tissue in the gastrointestinal tract, causing chronic inflammation. It affects young individuals, and, even though it is not curable, it can be treated and controlled by medications and surgery.

Epidemiology and origination of Crohn’s Disease

Crohn’s is considered to be a complex disease with both genetic and environmental risk factors. There is extensive evidence to support the role of genetics in the development of Crohn’s disease. Having a relative with Crohn’s disease is the greatest risk factor for other family members. Also, studies of twins have shown that identical twins, who share almost 100% of their genetic information, were more likely to both have the disease than fraternal twins.  The differences in the prevalence of Crohn’s in various racial and ethnic groups further indicate that genetic factors contribute to the risk, even though shared cultural factors, such as diet and lifestyle, might also explain these differences. Specifically, the prevalence of Crohn’s disease in European countries ranges between 1 and 12 per 100,000 individuals, whereas this disease was until recently virtually unknown in the developing countries.

The major genetic risk for Crohn’s disease identified so far is conferred by 3 rare mutations in the NOD2 gene. NOD2 plays an important role in the immune system, as it enables immune cells to recognize bacterial molecules and stimulates an immune reaction. While the frequency of these mutations ranges between 1% and 4.5% in the general population, about 40% of Crohn’s disease patients carry at least one copy. This translates to a 2 to 4-fold risk of developing the disease in carriers of one copy and a 10 to 40-fold risk in those who carry multiple copies of these mutations. Recent advances in the field of genetics have allowed identification of an additional 160 genetic variants associated with Crohn’s disease in individuals of European ancestry. However,  a sharp increase in the occurrence of the disease in children of immigrants from the developing countries who move to Western countries, as well as the well- established effect of smoking on Crohn’s disease risk, suggest a prominent role for environmental factors as well, most likely diet and lifestyle.

Crohn’s Disease in the Ashkenazi Jewish Population

Interestingly, Jews of European descent (Ashkenazim) have a 4 to 7-fold increased risk of developing Crohn’s disease compared to non-Jewish Europeans. Genetic risks alone could not explain why the prevalence of Crohn’s disease is so much higher in Ashkenazim than in surrounding populations. To investigate this phenomenon, researchers from the Mount Sinai School of Medicine have recently conducted the largest study which compared 1,878 Ashkenazi Jews with Crohn’s disease to 4,469 Jews without the disease, using DNA samples to evaluate their genetic make-up. They discovered five new genetic risk regions associated with Crohn’s disease in Ashkenazim. Armed with this new information, they can begin to pinpoint additional causal genetic mutations, discover the nature of the malfunctions they create,  and hopefully eventually develop new treatment approaches. That study also demonstrates the value of genetic studies in isolated populations, like Ashkenazi Jews.

 

The Role of Commensal Bacteria in Crohn’s Disease Risk

One possible explanation for the origination of Crohn’s disease is the hygiene hypothesis which suggests that a lack of early childhood exposure to infectious agents causes the immune system to wrongfully recognize its own non-pathogenic microorganisms as imminent risks and to act against them, causing substantial damage. This notion is particularly interesting in light of accumulating evidence suggesting that the identity and relative abundance of members of bacterial communities, or microbiota, normally residing in the human body and referred to as “commensal”, or non-harmful, bacteria, can be associated with different disease states. Microbial cells that live on (skin, eyes) and inside the human body (digestive system) may outnumber the quantity of human cells by 10-fold. This means that we may be carrying more bacterial genes than our own. Some commensal bacteria are essential for our health and provide a wide range of metabolic functions that the human body lacks. They help break down, absorb and store nutrients that otherwise cannot be digested, fight pathogenic bacteria, and play an important role in the development of the immune system.

About the Author: Inga Peter is the Associate Professor in the Department of Genetic and Genomic Sciences at the Mount Sinai School of Medicine. Her research interest is to identify variations in the human genome that can explain susceptibility to common diseases such as obesity, diabetes, and Crohn’s disease that can lead to early prevention and personalized treatment of these conditions. She graduated from Tel Aviv University and completed her training at Tufts University in Boston. She lives in Westchester County, NY with her husband and 3 sons.


If you don't see your comment after publishing it, refresh the page.

Our comments section is intended for meaningful responses and debates in a civilized manner. We ask that you respect the fact that we are a religious Jewish website and avoid inappropriate language at all cost.

If you promote any foreign religions, gods or messiahs, lies about Israel, anti-Semitism, or advocate violence (except against terrorists), your permission to comment may be revoked.

No Responses to “Broader Lessons from Genetic Studies of the Ashkenazi Jewish Population”

Comments are closed.

SocialTwist Tell-a-Friend

Current Top Story
Jihad boy, age 13, poses with assault rifle in ISIS propaganda photo.
ISIS Urges Muslims Worldwide, ‘Kill A Disbeliever’
Latest Sections Stories
Calmer Times. Breslov chassidim on erev Rosh Hashanah in 2012 at the grave of Rav Nachman in Uman.

As optimistic as Menachem Rosenberg is – and he said he is going to Uman – he’s sure that this year, most of the travelers will not tour other religious sites or places in Ukraine.

Three sets of three-day Yomim Tovim can seem overwhelming – especially when we are trying to stay healthy.

Plotkin-092614

Is a missed opportunity to do a mitzvah considered a sin?

The sounds and scents of the kitchen are cozy, familiar, but loud in the silence.

Everyone has a weakness. For some people it is the inability to walk past a sales rack without dropping a few hundred dollars. For others, it’s the inability to keep their house organized.

Not enjoying saying no, I often succumbed to requests viewing them as demands I couldn’t refuse.

His entire life was dedicated to Torah and he became a pivotal figure in the transmittal of the Oral Torah to the next generation.

When you don’t have anyone else to turn to… that’s when you’re tied to Hashem the closest.

While we all go to restaurants for a good meal, it is dessert, that final taste that lingers in your mouth, that is the crown jewel of any dining experience and Six Thirteen’s offerings did not disappoint.

Today, fifty years and six million (!) people later, Israel is truly a different world.

There will always be items that don’t freeze well – salads and some rice- or potato-based dishes – so you need to leave time to prepare or cook them closer to Yom Tov and ensure there is enough room in the refrigerator to store them.

In Uzbekistan, in the early twentieth century, it was the women who wore the pants.

More Articles from Dr. Inga Peters

This year marks the 80th anniversary of the influential paper published by a Mount Sinai physician, Dr. Burrill Crohn, and his colleagues that for the first time characterized a disease associated with severe inflammation of the intestine. Patients with what was later named Crohn’s disease develop diarrhea, fever, stomach pain, and often lose weight. Crohn’s is now classified as an autoimmune condition in which the immune system attacks its own healthy tissue in the gastrointestinal tract, causing chronic inflammation. It affects young individuals, and, even though it is not curable, it can be treated and controlled by medications and surgery.

Printed from: http://www.jewishpress.com/sections/health/broader-lessons-from-genetic-studies-of-the-ashkenazi-jewish-population/2012/08/12/

Scan this QR code to visit this page online: