04 February 2013
ByAppeared in BioNews 691
Genealogy experts will demonstrate the test at the Who Do You Think You Are? Live heritage exhibition at London's Olympia later this month. The test will analyse the gene MC1R, which affects the production of red pigment, allowing couples to determine if they could conceive a child with red hair.
Dr James Wilson, a geneticist from BritainsDNA told the Daily Mail, 'Through a simple saliva test to determine deep ancestry, we can also identify whether an individual is a carrier of any of the three common redhead variants in the gene MC1R'.
Four in ten British people carry these gene variants despite not having red hair themselves. The variants show recessive inheritance, explained Dr Wilson to the Telegraph: 'This means that families can carry a variant for generations, and when one carrier has children with another carrier, a redheaded baby can appear seemingly out of nowhere'. There is a 25 percent chance of two carriers conceiving a child with red hair.
The variants inactivate the gene MC1R, which disrupts a pathway important for the production of the pigments black melanin and red/yellow melanin. This prevents the production of black melanin while allowing the production of red/yellow melanin, resulting in red hair, light skin and often freckles.
BritainsDNA aims to establish exactly how many British people carry three of the most common redhead variants of the MC1R gene and then publish a map indicating where these variants are most common across Britain. About ten percent of Irish people have red hair, but BritainsDNA reports that up to 46 percent are carriers of the redhead variants. In England, it is estimated that six percent of the population have red hair but there are no current figures available for the number of potential carriers.
The test may also indicate whether a couple's offspring have an increased risk for certain health issues. Recent research shows that the MC1R gene is associated with a higher incidence of skin cancer, which may be independent of exposure to ultraviolet radiation. Dr David Fisher, lead author of the study investigating the MC1R gene in mice told Nature: 'There is something about the redhead genetic background that is behaving in a carcinogenic fashion, independent of UV'.
Alistair Moffat, one of the founders of BritainsDNA, emphasised the historical legacy he thinks the project could unearth, as reported by the Telegraph: 'Those who actually have red hair only need to look in the mirror but very many more carry a redhead gene variant but don't know they have it and could pass it on to their children. We aim to discover this hidden story of the Red-Headed Nation'.