From the Latin word consanguinitas, consanguinity is defined as ‘blood relation,’ as an another individual being descended from the same ancestor carrying some or a few similar genes. Accordingly, consanguineous marriages are a union between two individuals who are related; be it first or second cousins relating from the same progenitor when they look back into and carefully observe their family tree right from a few years ago.
Theologically, according to Islam, Prophet Muhammad (PBUH) married Zainab bint Jahsh, who was his first cousin. According to Christianity, Mother Mary was married to Saint Joseph, who was her first cousin with the same ancestral line. According to Judaism, Jacob married Rachel and Leah, who were his first cousins.
As stated by research, one billion of the present population live with a preference for consanguineous marriages as it is seen not only as a form of tradition to be followed with due respect, but also as a form of high esteemed etiquette in certain communities of North Africa, Middle East and West Asia. Although not a single religion has actually prohibited consanguineous marriages, it has now become a matter that has to be paid more attention to in today’s era as a result of genetic disorders connected to intellectual and developmental disabilities making it a very unfavorable situation for both, parents and their offspring.
Infant mortality rate, birth defects, learning difficulties, blindness, hearing problems and metabolism disorders are some of the usual medical problems diagnosed in the offspring of those parents who are the first or second cousins of one another. And this problem is high among children born in Britain’s Pakistani community as is their culture of usually getting married to either their first or second cousins without actually being aware of the consequences on their children later on due to the risks and disasters of consanguineous marriages not being openly discussed as a result of its possibilities of offending the Muslims, according to Baroness Deech.
Channel 4’s Dispatches program related to the research about cousin marriages in the United Kingdom tragically found that about 70 British studies have proved the risks of consanguineous marriages resulting in 700 children being born with either one or more than one sort of recessive genetic disorders every year.
On the other hand, according to few other researches, 4-7% of children from first cousins are likely to have birth defects while 3-4% of children from distantly related parents are likely to have the same birth defects. It is also believed about how first cousins share 12.5% of DNA, second cousins share 6.25% of DNA and third cousins share 3%. This indicates that the farther the relationship of cousins, the lesser DNA they share which is believed to reduce the possibilities of recessive disorders and genetic disabilities in their children.
A research conducted in 2013 to check the relationship between consanguinity and down syndrome proved about how there was a higher frequency of down syndrome among the non-consanguineous marriages in comparison with the consanguineous marriages. This pinpoints about how consanguinity was not a significant factor of the occurrence of the higher percentage of Down Syndrome disease. Contrarily, on another qualitative study based on British-Pakistanis carried out on 2015 to addressing the key issues in the consanguinity-related risks of autosomal recessive disorders in consanguineous communities made it clear about how recessive disorders are transmitted by parents who carry one copy of a gene that can cause a disorder. When both parents carry the same gene for the disorder, every child they have has a 25% risk of suffering from that recessive disorder. This study also included the reason to why many parents who married within family didn’t know about recessive disorders and their causes were because there wasn’t a proper tool of communication for them as a medium of explaining the consequences of how, what and why their children will be affected with disorders in the future by professionals and doctors in that field.
Hence, the reason to whether or not consanguineous marriages ‘often’ result in genetic disabilities is yet to be resolved due to the fact that there are yet a few other cases in which children born out of consanguineous marriages have also been affected with the same disorders. The only way to get an early prevention for cousins getting married from the same ancestral line is to go for a genetic screening program prior to getting married to either of their cousins: First, second or extended.