Red hair

# What is red hair? Red hair is a rare hair color that only occurs in a small percentage of people worldwide. This hair color is characterized by a distinctive shade of red to orange, which can range from light copper tones to darker, deeper shades of red. People with red hair often have very fair skin, which is more prone to sunburn and freckles. Red hair is particularly common in certain geographical regions, especially in parts of northern and western Europe. In these regions, the proportion of the population with red hair is higher than the global average. Historically and culturally, people with red hair have been perceived differently in different societies. While they were revered in some cultures, they often faced prejudice in others. Today, red hair is considered a unique and striking hair color that attracts special attention. The biology behind hair color is influenced by the production and distribution of pigments in the hair. Melanin, the main pigment that determines hair color, occurs in two forms: Eumelanin, which is responsible for darker hair colors such as brown and black, and pheomelanin, which is responsible for red and yellowish hair colors. Red hair is created when the amount of eumelanin is low and pheomelanin predominates. # Cultural perception Red hair is associated with a variety of myths and stereotypes in different cultures. In European folklore, people with red hair were often seen as particularly spirited, impetuous or even magical. These attributions are reflected in literature and art, where red hair was often used to depict characters with special qualities or extraordinary abilities. In other cultures, such as in parts of Asia, red hair tends to be seen as an exotic or unusual phenomenon that arouses curiosity and admiration. > ## Good to know > > Red hair is so rare that it only occurs in around 1-2% of the world's population. In addition, people with red hair produce unique vitamin D through sunlight, which gives them additional advantages in northern latitudes. # Biological characteristics In addition to the striking hair color, people with red hair also have some biological peculiarities. Not only is their light-colored skin more susceptible to sunburn, there is also evidence that they may be more sensitive to pain. This increased sensitivity to pain has been observed in some studies and could be related to an altered function of the pain receptors. There is also evidence that red-haired people are often more resistant to certain anesthetics, which is of particular interest in medical contexts. # What does genetics have to do with it? The genetic basis of red hair is based on specific variants in the melanocortin-1 receptor gene (MC1R), in particular five key single nucleotide polymorphisms (SNPs): rs1805009, rs1805008, rs1805006, rs11547464 and rs1805007. These SNPs have a decisive influence on the function of the MC1R receptor and play a central role in determining hair color. The SNP variant rs1805009, known as R151C, alters an amino acid in the receptor and reduces its ability to activate enzymes that promote the conversion of pheomelanin to eumelanin. This leads to increased production of pheomelanin and contributes to reddish hair color. Similarly, SNP rs1805008, also known as D294H, affects receptor activity by decreasing the function of the MC1R receptor, thereby increasing the tendency to form red hair. The SNP rs1805006, known as R160W, affects receptor function by altering receptor structure, thereby reducing ligand binding and signaling. This leads to an overproduction of pheomelanin, which is reflected in the visible reddish hair color. Another important SNP, rs11547464 (R163Q), leads to a functional impairment of the receptor and thus to increased pheomelanin production. Similarly, rs1805007 (I155T) alters receptor function, leading to reduced activity of the MC1R receptor and favoring the formation of red hair.