Is Marrying Your Cousin Actually Dangerous?

What did Queen Victoria, Charles Darwin and Albert Einstein have in common? They all married their first

cousin

s. You think Darwin, of all people, would know better. After all, mating with a close relative passes on bad genes that lead to deadly genetic mutations today when you marry

your

first

cousin

. It's illegal in 24 US states, but for most of Western history people had to marry whoever lived nearby, which often meant

marrying

within the extended family. In fact, between 1650 and 1850, the average married couple were fourth cousins, so they had the same great-great-grandfather. grandparents genetically speaking, that means they shared 0.2% of their DNA, not much when you compare it to second third cousins ​​and especially first cousins, and the more DNA you share, the greater the chance that

your

offspring will have a disease genetics such as cystic fibrosis or sickle cell anemia, but here it is What you don't have to be sick to pass on a genetic disease to your child is cystic fibrosis, it is caused by a defect in the CFTR gene, but you need two copies of the gene defective to contract the disease, so if you only have one defective copy it does not affect you, instead you are what is now called a carrier.

If a carrier is paired with a non-carrier, there is no risk of the children getting sick, but when both parents have a defective copy of CFTR, the children have a 25% chance of inheriting. two copies of the gene and have the disease, so to see how

dangerous

it is to marry your first cousin, we need to calculate the chances of two first cousins ​​carrying one copy of the same genetic disease, since they share a set of grandparents. Start there now, it becomes a game of what if both grandparents are carriers versus just one, if one of your children is a carrier versus none at all and what happens if those children marry other carriers or not, it can get complicated very quickly .

But scientists have crunched the numbers and it turns out that the risk of cousins ​​having a child who inherits a genetic disease is four to seven percent for the general population, it's three to four percent, so it's not a big deal. , here's the problem, it's the odds for a genetic disease, but there are thousands that could be hidden in your family tree, plus, if your children also marry their first cousins ​​and your children marry their first cousins, it's a recipe for disaster because instead of introducing potentially useful new genes into the family gene pool, we are recycling old and possibly

dangerous

ones.

For example, Emperor Ferdinand I of Austria, his parents were twice first cousins ​​and when he was born he was not especially healthy, so when it comes to

marrying

your cousin, you shouldn't make it a Family Tradition What interesting things have you discovered in your family tree? Let us know in the comments.