3 Myths of Genetics


Myth 1:  Genetic=Hereditary

FALSE. As a genetic counselor, I see countless patients who use the words “genetic” and “hereditary” interchangeably. It is the lack of differentiation between these two words that can be a source of confusion for many individuals.  According to Merriam-Webster dictionary, the word genetic is defined as “of, relating to, caused by, or controlled by genes” while the word hereditary is defined as “passed or able to be passed from parent to child before birth”. Having those definitions in mind, it is important to remember that not all genetic conditions are hereditary. While an individual may have a health condition or genetic syndrome due to a change in their genetic make-up, it does not mean they will pass it down, nor does it mean their other family members may be at risk to pass it down. It is very important to differentiate between these two words and use them appropriately when discussing your personal and family health history.

Myth 2: Carriers of a genetic condition are affected

FALSE. We all have two copies of every gene, one from our mother and one from our father. When an individual is said to be a carrier of a genetic condition, this means that one copy of their gene is not working properly. This individual is not affected with the condition and will likely not have any symptoms because they still have their other copy of their gene working just fine. In order for an individual to be affected with the condition, both copies of their gene must not work properly. These types of disorders are inherited in what is called an autosomal recessive manner.  Just because an individual is a carrier of a condition it does not mean their children will be affected. It would depend on the carrier status of their partner, and even then it is not a guarantee they will have an affected child together.

As part of my Masters thesis through University of California Irvine, I conducted a survey of the Persian Jewish community to measure their perception of their risk for genetic disorders and to study their attitudes toward carrier testing. Participants were asked to evaluate whether genetic disorder carrier status would harm their relationship with their community or hinder their ability to find a marriage partner. Overall, 61% of participants (n=103) did not believe that genetic carrier status would harm their relationship with their community. However, 86% (n=146) believed that a being an unaffected carrier for a genetic disorder would harm their chances of marriage. In fact, their fears were corroborated in a later question; when the participants were asked if they would approve of a family member marrying an individual who is known to be a carrier of a genetic disease, those who were 45 years of age or older were more likely to disapprove of this union.

This age group represents our parents, grandparents, aunts and uncles. There have been many stories of couples breaking up due to disapproval from family members. How many of those couples could have been spared heartbreak if there was proper genetic education in their community? There are many resources available to individuals who want to learn more about their family history and their risk to be a carrier for a genetic condition. Genetic counselors can serve as a source of information and guidance. If you are interested in finding a genetic counselor near you, visit www.nsgc.org.

Myth 3: Only the Ashkenazi community is at risk to be a carrier for genetic conditions

FALSE.  It is a commonly known fact that the members of the Ashkenazi community have a higher chance of being carriers for genetic conditions such as Tay-sachs disease, Gaucher and cystic fibrosis.  Students attending Jewish high schools are often presented with the opportunity to learn about carrier screening and even attend screening events. Since the implementation of carrier screening for Tay-sachs disease in the 1970’s, there has been a 95% reduction in the number of babies born in the US with Tay-sachs.  Similarly to the Ashkenazi population, the Sephardic community is also at a higher risk to be carriers for a specific subset of genetic conditions.

Within the Persian Jewish community, there are actually five such conditions:

(1) Hereditary inclusion body myopathy (HIBM)- A hereditary muscle disorder with a carrier rate of 1 in 20 Persian Jews.

(2) Wolman disease- The improper breakdown and use of fats and cholesterol in the body. Rare worldwide but found more commonly in the Persian Jewish community.

(3)Congenital hypoaldosteronism-  A salt-losing disorder with a carrier rate of 1 in 30 Persian Jews.

(4) Polyglandular deficiency- A multiple hormone deficiency with a carrier rate of 1 in 50 Persian Jews.

(5) Pseudocholinesterase deficiency- An anesthesia sensitivity disorder with a carrier rate of 1 in 10 Persian Jews.

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This article was written by Shira Kohan and originally Published in The Skribe.