An article published in the journal “Nature Communications” describes a genetic research on the origin of the various hair colors in human beings. A team of researchers led by professors Ian Jackson and Albert Tenesa of the Scottish University of Edinburgh studied the hair-related genetic characteristics of 343,234 people who took part in the UK Biobank study, mainly linked to health research. Among the findings there are eight new genetic variants linked to red hair and variants of nearly 200 genes associated with blonds and brunettes.
The European populations are the ones that show by far the greatest variability in hair color, expressed by complex genetic traits. For example, the gene called MC1R is the main origin of red hair and previous studies showed that red-haired people inherit two versions of that gene – one from each parent – yet not all the people who have those two genes are redheads. There were still a number of questions on the subject those researches couldn’t answer.
Ian Jackson and Albert Tenesa’s team used the data gathered in the large UK Biobank genetic database to try to better understand the variants of genes such as MC1R, defined in jargon single nucleotide polymorphism (SNP), and their effects on people’s hair color. Various shades of color from black to dark brown, to light brown to blond are caused by genetic differences in nearly 200 genes.
The comparison with the genes of redheads allowed to discover eight new variants linked to them. The possibility of examining a huge amount of Britons that includes many redheads made it possible to better understand how the variants of the MC1R gene work and the interactions among different genes that contribute to red hair that were previously unknown.
The many genes studied don’t only affect the hair color’s tone with their variants but also other characteristics such as their texture, with various consequences on their structure and strength. Some of those genes regulate the way hair grows, for example, the presence of curls. The amount of genes that regulate these characteristics was the biggest surprise for the researchers.
Professor Ian Jackson stressed the importance of the UK Biobank’s size in his team’s discoveries. There are really a lot of genetic variants that regulate the Britons’ many hair color’s tones – and therefore of Britons’ descendants scattered around the world – so having such a hug database was crucial to get more answers than previous research.