How is red hair passed on genetically?

Some parents worry that their children will be born with a rare disease or a hidden genetic disorder. Other parents, however, wonder if their children will possess something more obvious: red hair. read more

Red hair is caused by a mutation in the melanocortin 1 receptor. It is a recessive trait, indicating that two copies of the mutation for red hair are necessary for red hair in a person (you must inherit a copy from your mother, and a copy from your father to be a red head). read more

Regardless of the definition, the frequency of red hair is highest in Ireland (10 to 30%) and Scotland (10 to 25%), followed by Wales (10 to 15%), Cornwall and western England, Brittany, the Franco-Belgian border, then western Switzerland, Jutland and southwest Norway. read more

The gene for red hair is recessive, so a person needs two copies of that gene for it to show up or be expressed. That means even if both parents carry the gene, just one in four of their children are likely to turn out to be a redhead. As a result, families that have no redheads for decades can suddenly discover a carrottop in their midst. read more