A Person with whom you share a grandparent (but not a parent) is a first cousin. For years, the argument that has been existing is whether it is safe to marry a first cousin. There were talks that marrying a first cousing has higher risk of getting diseases, even at birth. They were also supported by the facts and figures taken from various surveys conducted across the globes.
There are many who are willing to marry a first cousin, mainly because they believe that the relationship would be much better with a person whom they know. They have better understanding and they have a nicer emotional feel. When scientists are trying to explain the risk in such marriages, many groups of people are denying it.
Studies says that there are higher chances that childs born to first cousins can get genetic defects, which may lead to rare but dangerous diseases. It is found that the children born has 10 times more chance of getting serious disability as a result of genetic disorder. Recessive genetic disorders (RGD) result from inheriting two defective recessive alleles of a gene, one from each parent. Let us have a look at genetics little a bit. We need a copy of a trait from both parents. Of these two copies, both can be dominant genes or one dominant and other recessive, or both recessive. We need atleast one dominant copy of the trait for that trait to show in the offspring. Eg) we need atleast one Tall (dominant gene) from any one of the parent to make the offspring tall. If both the copies are recessive, then that trait will not show in the offspring. If there happened to be one of these recessive traits being carried in people in the family, with every generation there is a greater chance that two carriers could come together and each donate a recessive trait. In other words, there is a greater probability that this trait will show up in a close family mating than in the general population. So if a child inherits a copy of same variant gene it may develop one of the 1000s of known RGD. Since the first cousin share the same grandparent, there are more chance for getting the two recessive gene (if present) one from each parent. Hence the risk increases.
In another point of view, when first cousins are married, there won't be much diversity in genes and chances of getting offspring with better qualities are reduced. When people with great qualities are confined to a community, there are chances that we lose them as we move down the generation.
So if you are willing to marry your first cousin, consult doctor and get yourself tested for the safety of your generation. Prevention is better than cure.
There are many who are willing to marry a first cousin, mainly because they believe that the relationship would be much better with a person whom they know. They have better understanding and they have a nicer emotional feel. When scientists are trying to explain the risk in such marriages, many groups of people are denying it.
Studies says that there are higher chances that childs born to first cousins can get genetic defects, which may lead to rare but dangerous diseases. It is found that the children born has 10 times more chance of getting serious disability as a result of genetic disorder. Recessive genetic disorders (RGD) result from inheriting two defective recessive alleles of a gene, one from each parent. Let us have a look at genetics little a bit. We need a copy of a trait from both parents. Of these two copies, both can be dominant genes or one dominant and other recessive, or both recessive. We need atleast one dominant copy of the trait for that trait to show in the offspring. Eg) we need atleast one Tall (dominant gene) from any one of the parent to make the offspring tall. If both the copies are recessive, then that trait will not show in the offspring. If there happened to be one of these recessive traits being carried in people in the family, with every generation there is a greater chance that two carriers could come together and each donate a recessive trait. In other words, there is a greater probability that this trait will show up in a close family mating than in the general population. So if a child inherits a copy of same variant gene it may develop one of the 1000s of known RGD. Since the first cousin share the same grandparent, there are more chance for getting the two recessive gene (if present) one from each parent. Hence the risk increases.
In another point of view, when first cousins are married, there won't be much diversity in genes and chances of getting offspring with better qualities are reduced. When people with great qualities are confined to a community, there are chances that we lose them as we move down the generation.
So if you are willing to marry your first cousin, consult doctor and get yourself tested for the safety of your generation. Prevention is better than cure.