Gene Compatibility
Choosing whom to marry is, of course, a huge decision. The perfect candidate needs to meet many requirements – have a great personality, sharp wit, good looks… but are you gene compatible?
Are Your Genes Compatible?
Choosing whom to marry is, of course, a huge decision. The perfect candidate needs to meet many requirements – have a great personality, sharp wit, good looks, and a great-grandfather who’ll bequeath a fortune. Well… may be not the last one. A very important requirement is one that many people take seriously – being able to have healthy children. That’s why many Ashkenazi Jews choose to get tested for genetic diseases, such as Tay-Sachs.
Tay – Sachs disease is a sickness during which a newly born baby develops normally for about the first six months. But afterwards, the baby’s central nervous system – the brain and the spinal cord – begin to deteriorate. Eventually, the child cannot hear, see, or swallow. By the age of around four, the child is paralyzed and dies.
What is Tay-Sachs?
Tay-Sachs happens because children with the disease have a problem in their genetic information. Genetic information is stored in DNA, a spiral-like biological molecule inside every cell in a person’s body. The information gives instructions that the body needs – including the person’s height, weight, eye color, and even artistic and athletic talents. However, sometimes the DNA spiral can have mutations – changes – in its rungs. Such changes can corrupt the genetic instructions, making the body carry out harmful actions. In the case of Tay-Sachs, the mutation in the genetic instructions makes the body produce less of a certain substance (an enzyme called hexosaminidase A) needed to break down unnecessary molecules (the fatty acid derivative known as ganglioside). As a result, the molecules accumulate in the brain and prevent the brain from developing and functioning normally.
One Parent Carrier
There is no cure for Tay-Sachs, but luckily, genetic screening can prevent it. That’s because in order to get Tay-Sachs, a baby has to inherit it from his (or her) parents. All the traits that children have they inherit from their parents, who pass down the traits in the form of genetic information. Each child gets two sets of information – one from the mother and one from the father. The reason why kids are so different from their parents (and from their siblings) is because the two sets have a myriad ways of mixing with each other to produce many different combinations. In addition, some genetic information might remain hidden in the parents but comes out in the children. This happens because some information is “stronger” – more dominant – than other. For example, brown eye color is “stronger” than blue, and it wins. So, if one parent has brown eyes, and the other has blue, the child is likely to have brown eyes. However, if both parents have blue eyes, there’s no “strong” eye color to battle with the weaker blue eye color, and blue eye color wins. So, children whose parents both have blue eyes will almost certainly have blue eyes. But even a child of a brown-eyed and blue-eyed parent still has a chance. That’s because he (or she) inherits the blue-eye information from the blue-eyed parent, but this information stays hidden. If he (or she) marries someone with blue eyes – or even someone with brown eyes who has blue-eyed hidden information – this hidden genetic information might be passed down to his (or her) kids and mix with the genetic information of the spouse in such a way that will make his kids have blue eyes.
Getting dizzy with all the eye color? The important thing to know is that genetic information that tells a body to have Tay-Sachs is of the weak kind, like for blue eyes. This means that even if a person inherits such hidden information, he still has pretty good chances of being healthy. In order for him to actually have Tay-Sachs, he would have to inherit the information from both parents. If he inherits it only from one parent, he’ll be healthy, but he will still have the information hidden inside him, which is called being a carrier. If he marries another carrier, they have a 25% chance of having children with Tay-Sachs. That’s one out of four children dying before age five. So, what are your chances of being a carrier, and can you find out for sure whether you are one? One in 25 Ashkenazi Jews is estimated to be a carrier. Other Diseases Tay-Sachs is not the only disease that is unusually prevalent among Ashkenazi Jews. Other diseases that are inherited similarly and bear similar odds include Canavan Disease and Familial Dysautonomia. These diseases too affect the nervous system. Still other prevalent genetic diseases can cause mental retardation and predispose children towards leukemia. That’s why it’s so important to get tested.
Testing through Jewish Organizations
You can find out whether you are a carrier through a simple blood test. However, if you’ll turn out to be a carrier, no doubt you will worry – but why do that if your chances of meeting another carrier are just one in 25? A less stressful alternative is to take the test through an organization like Dor Yeshorim, which does not reveal to you the results of the test. When you think you’re getting serious about marrying someone, encourage him (or her) to take the test through the same organization (if he didn’t do so already), and the organization will then tell you whether you are a good match. Chances are you will be – after all, the chance that you are both carriers is one in 625! Despite the good odds, the test is still important since it prevents unnecessary suffering and tragedy. In fact, in 2003, there were no Jewish babies born with Tay-Sachs in North America and in Israel there was only one baby. So, take control of your future and good luck!
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