The incidence of first-cousin union in that community is now declining," he said. Partly that would be because of gradual adaptation to Norwegian culture, but since when the study was published, there had been a health education campaign to inform people of the risks. This article is more than 8 years old.
Study of 13, babies born in Bradford concludes cultural practice in Pakistani community outweighs effects of deprivation. Bradford Royal Infirmary, where the babies who were the subject of the birth defect study were born.
Other factors could be at play, however. Erlich says that, according to his data, many continued to marry their cousins even after the Industrial Revolution dramatically improved mobility. While proximity may be one key to romance, it seems consolidating money or power played an important part in family marriages, too. Erlich believes it was changing social norms—and the advent of this cousin marriage taboo—that finally pushed people to look beyond their village and their family.
Other factors, including the increasing autonomy of women and shrinking family sizes which left fewer cousins to marry could also have been involved. Whatever the underlying cause, by the end of the Civil War, many states moved to outlaw cousin marriages. Today, 24 states ban marriage between first cousins, while 20 states allow it.
The others allow first cousins to couple up, but only under certain circumstances. And, of course, even in states where it is legal, the practice is taboo. First cousins share This is likely due to the dramatic increase in birth defects, genetic conditions and health problems seen in children of these matings.
UHealth Miller School. Genetics Awareness Project. Home What is Genetics? So the risk of a child inheriting two copies of a dangerous allele is elevated compared to non-related marriages since they have a greater chance of inheriting the same recessive allele from their common ancestors.
Nevertheless, British authorities determined that despite the increased risk, most children of cousin marriage are healthy. Privacy Policy Contact Us You may unsubscribe at any time by clicking on the provided link on any marketing message. Bittles and M. Black tackled consanguineous marriage on a global scale in a paper in Annual Review of Anthropology.
For the reasons discussed above, beyond just dangerous recessive alleles, the odds of a child of first cousins inheriting two copies of the same allele—any allele, whether recessive or not—is elevated. Populations with fewer consanguineous marriages have higher heterozygosity, meaning individuals carry two different alleles for a given gene.
Unmasking is less common in highly heterozygous populations, so according to Bittles and Black, as cousin marriage declines, there should be corresponding increases in human health at a population level. The bottom line is that it is often safe to have children with your cousin, but doctors do recommend genetic counseling for prospective first cousin parents.
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