Is it possible to marry a relative

Marriage between close relatives increases the chance of certain genetic concerns. Specifically, it increases the chances of having a child with a recessive condition. You may remember from biology class that DNA is the instructional manual that tells our body how to grow, develop, and work properly. Genes are the individual units that make up our DNA. We all have two copies of every gene: one from mom and one from dad.

Some variants are responsible for physical differences, such as hair or eye color. And some DNA variants cause diseases. Sometimes, having a variant in just one copy of a gene is enough to cause a disease. But for recessive conditions, a person will only develop a disease when they have mutation in both copies of gene.

For individuals to have recessive condition, they must have two non-working copies of a gene. We each carry about 12 genetic variants associated with recessive conditions. But if you marry someone who has the same recessive variant as you, there is a chance your child may have the condition. The more DNA you share with someone, the more likely it is that you have the same disease-causing variants. Studies of cousin marriages worldwide suggest that the risks of illness and early death are three to four percent higher than in the rest of the population.

But the risks apply primarily to couples who are carriers of disorders that are normally very, very rare, Bittles explained. What's more, many studies of the effects of cousin marriage fail to account for the influence of non-genetic factors on infant health, such as socioeconomic status, maternal diet during pregnancy, and infections. Scientists estimate that the first people to migrate out of Africa numbered to 10, breeding-aged individuals.

Given those small numbers, and the fact that these people likely dispersed in small hunter-gatherer groups and often married within their clan or tribe, "it seems inevitable that some level of close kin mating would have occurred," Bittles writes. Bittles is now studying the effects of kin mating in early humans and the genetic consequences for people living today at the U. One surprising and oft-neglected advantage of marriage between close biological relatives is a phenomenon called purging, in which disease genes are exposed and removed from the gene pool.

You can find more about the different legal ways of getting married in Ireland and the notification requirements for marriage. If you have a question about this topic you can contact the Citizens Information Phone Service on 07 Monday to Friday, 9am to 8pm. You can also contact your local Citizens Information Centre or Request a call back from an information officer. Introduction Marriage is a legally binding contract that will affect both parties and, to a certain extent, their children for all of their lives.

Rules For a marriage to be legally valid in Ireland the parties to the marriage must: Have the capacity to marry each other Freely consent to the marriage.

Free consent may be absent if, at the time of the marriage, a person is suffering from intoxication, brain damage, mental disability, mental instability or insanity to the extent that they are not able to understand the implications of marriage.

Additionally, if someone agrees to marry because of threats or intimidation, their apparent consent may also be invalid and the marriage may be void. Observe the necessary formalities Capacity to marry To be legally entitled to marry, both of you must fulfil all of the following requirements at the time the marriage takes place. Both parties must: Be over 18 years of age. Have given the Registrar 3 months' notification of the marriage or have a Court Exemption Order if this is not the case and have been issued by the Registrar with a Marriage Registration Form.

A couple whose civil partnership was registered in Ireland do not have to give the 3 months' notice. Be either single, widowed, divorced , a former civil partner of a civil partnership that ended through death or dissolution , or have had a civil annulment of a marriage or civil partnership or a valid foreign divorce or dissolution.

If you are marrying your civil partner you do not need to have your civil partnership dissolved before marrying. It will be automatically dissolved when you marry.

Have the mental capacity to understand the nature of marriage Not be related by blood or marriage to a degree that prohibits you in law from marrying each other.

But the odds of healthy offspring dramatically improve with each new distance of relation. Second cousins share only 6. Seventh cousins—the average distance between modern American spouses—have no meaningful genetic relation at all. The genetic data, branching off this way and that, reveals just how closely related we all already are. Small innovations can go a long way. Sign up to receive Popular Science's emails and get the highlights.

Albert Einstein and his second wife and first cousin , Elsa Einstein, took family marriage to a new level. They were related through both maternal and paternal lineages: Their mothers were sisters and their fathers were first cousins. Wikimedia Commons. This story has been updated.