Marrying a first cousin would become illegal in Britain under a proposal brought to Parliament.
On Tuesday, Conservative MP for Basildon and Billericay, Richard Holden, will set out plans for his Bill that states how such unions result in a higher rate of birth defects, meaning their legal status should be reconsidered.
‘Studies show that it is associated with approximately double the rate of birth defects compared to the general population and can reinforce negative structures and control women,’ he said.
Marriages between certain blood relatives — as well as some step relationships — is already illegal in Britain.
However, it is still legal to marry your cousin in the UK, despite the health risks.
Data suggests the risk of a child of first cousins developing a genetic condition is between 3 to 6 per cent, which is double the risk of compared to children from unrelated parents.
While this still means the majority of children born in such circumstances will be healthy, the increased risk is undeniable.
Potential conditions children of first cousins are at increased risk of include birth defects, developmental delays, and ongoing genetic disorders.
One of the most famous modern day examples of inbreeding related to cousin marriage is the Whittaker family from Odd, West Virginia. Left to right is Danny Rae, Timmy Allen and Freddy Lee who are descended from a family tree featuring such unions
These can include as blindness, hearing loss, neonatal diabetes, limb malformations, low IQ, cleft palate, heart conditions, cystic fibrosis, and even an increased risk of infant death.
Risks broadly increases if there is a family history of such unions, as genetic errors can compound between generations.
During conception, children receive one copy of genes from each parent, with the harmful genetic mutations typically overridden by healthier genes.
But when closely related individuals have a child there is a decrease in genetic variation, resulting in an increased risk these harmful mutations remain and cause problems.
Cousin marriage is still common in some UK communities.
Experts have previously found a preference for such unions among British Pakistanis was a contributing factor in child mortality rates in Bradford due to an increased risk of genetic conditions.
NHS studies between 2007-11 found consanguineous marriages, a genetics term meaning parents are at least second cousins or more closely related, accounted for 60 per cent of marital unions in people of Pakistani heritage in Bradford.
This compared to just 1 per cent among white British couples in the area.
This graphic, from NHS material disturbed to couples in Bradford, explains some of genetic risks of having children with a close relative. Two parents with a recessive gene have an increased change of having a child with an inherited condition
An NHS website hosting the Born in Bradford (BiB) research project describes marrying your cousin is a cultural practice similar to White British women and couples choosing to have kids after the age of 34, another risk factor for genetic conditions
Of the Pakistani-heritage marriages, 37 per cent were specifically to a first-cousin and would be the type of unions that Mr Holden’s bill would forbid if passed into law.
Subsequent NHS studies, conducted between 2016 and 2020, found the rate of consanguineous unions among this community has fallen to about 43 per cent.
The NHS has previously stated cousin-marriage cousin accounts for about a third of birth defects in leaflets distributed to families in Bradford.
Under a scheme tracking rates across the area, health chiefs describe cousin marriage as a cultural practice.
Wording, still available online today, states a cousin marriage no different than white British people choosing to have children over the age of 34, in terms of increasing the risk of genetic conditions in a baby.
Worldwide, one in 10 people are thought to be the result of a consanguineous union.
Studies have put Pakistan as having one of the highest rates globally at 65 per cent of unions.
This is followed by India (55 per cent), Saudi Arabia (50 per cent), Afghanistan (40 per cent), Iran (30 per cent) and Egypt and Turkey (20 per cent each).
This map, by Professor Alan Bittles an Australian expert in genomics, shows rates of consanguineous marriage, that between cousins, around the world
Other data sets used by genetic experts studying consanguineous marriage have put the UK as having a rate of 1 to 4 per cent, while the US has a lower rate of less than 1 per cent.
First cousin marriages were once far more common and include some famous historical figures.
The father-of-evolution Charles Darwin married his first cousin Emma Wedgwood, and the famous physicist Albert Einstein married his first cousin Elsa Lowenthal.
Authors Edgar Allan Poe and H.G. Wells were also known to have married their cousins.
The British Royal family have also, like many among the European nobility, engaged in consanguineous unions.
Queen Victoria and Prince Albert were first cousins, sharing a set of grandparents.
In more modern times, former Iraqi dictator Saddam Hussein’s first wife was his cousin Sajida Talfah.
Musician Jerry Lee Lewis, of ‘Great Balls of Fire’ fame controversially married his cousin Myra Gale Lewis Williams when she was just 13, he was 22 at the time.
One of the most famous modern day examples of cousin-related inbreeding is the Whittaker family from Odd, West Virginia.
Siblings Ray, Betty, Larry and Lorene, as well as her son Timmy, are struggling with heartbreaking mental and physical conditions.
The siblings are the descendants of two sets of first cousins who got married. DailyMail.com previously revealed the bloodline continued with a set of identical twin brothers whose children got married.
John and Henry Whittaker were born in 1897. John went on to marry his own first cousin Ada Riggs – the daughter of Mary Perkins, who was the sister of John and Henry’s mother Eliza.
Ada and John had nine children, including Gracie Irene Whittaker who was born in 1920. John’s brother Henry married Sally Burton and they had seven children, including John Emory Whittaker, born in 1913.
Gracie and John were first cousins, but married in November 1935 and had their first child in 1937, having 15 in total.
Many members of the family have suffered from a heart attack, while two did not make it through infancy.
Some of the 15 children died early of an array of illnesses, including heart attack and cancer, believed to be tied to inbreeding.
While cousin marriage remains legal in the UK, incest — the sexual intercourse between immediate relatives — is illegal in Britain even if consensual.
Scientific titans Charles Darwin (left) and the famous physicist Albert Einstein (right) both married their first cousins
Queen Victoria and Prince Albert were first cousins, sharing a set of grandparents
Former Iraqi dictator Saddam Hussein’s (left) first wife was his cousin Sajida Talfah. Musician Jerry Lee Lewis (right), of ‘Great Balls of Fire’ fame also controversially married his cousin Myra Gale Lewis Williams when she was just 13, he was 22 at the time
However, inbreeding in Britain is probably more common than you think.
One academic study examining rates of ‘extreme’ inbreeding – where parents of a child are considered to be first- or second-degree relatives – found 125 Brits out of a sample of 450,000 were the result of such unions.
First degree relations include those between parent and child, while second-degree includes more distant, but still genetic close relatives, such as half-siblings.
Extrapolated to the wider population, the 2019 study was reported as meaning some 13,000 Brits were conceived through extreme inbreeding.
The authors noted, given the nature of the subject and the limited variety of Brits included in the sample, true rates could be significantly higher or lower.
Of the 125 Brits identified, about 43 per cent were found to be the result of the first-degree relations.
Some were adopted as children and thus likely had no idea of their parentage.
An increased interest and availability of DIY genealogy kits, enabling people to track their genetic family history, is leading some people uncovering uncomfortable truths about themselves and their relations.
Some have discovered they are the result of an incestuous union, or in other shocking cases learning they have married or had sex with someone who later turned out to be a close genetic relative.
