New Regions of the Human Genome Linked to Skin Color Variation in Some African Populations

In the first study of its kind, an international team of genomics researchers has identified new regions of the human genome that are associated with skin color variation in some African populations, opening new avenues for research on skin diseases and cancer in all populations. 

The findings may help researchers determine if humans with certain DNA sequences are more or less susceptible to DNA damage caused by ultraviolet radiation (UVR) or respond to cellular stress differently. NIH researchers contributed to this effort, led by Dr. Sarah Tishkoff at the University of Pennsylvania. The findings were published Oct. 12 in Science.

Studying human skin pigmentation helps researchers understand how the cells that produce skin pigment—melanocytes—and genes work together to protect skin from the damaging effects of UVR. Because equatorial regions receive approximately two times more UVR than more temperate regions, darker pigmentation in people from these regions is thought to reduce skin damage and cancer. In contrast, lighter pigmentation of people in northern countries may increase the production of vitamin D3 needed to prevent rickets, a softening and weakening of bones in children, usually due to inadequate vitamin D.

Researchers studying genes that contribute to skin color for the last hundred years have focused on analyzing differences among European populations. This study of ethnically diverse populations in Ethiopia, Tanzania and Botswana has shed light on regions of the genome not previously associated with skin color.

“This is transformative research because it provides new pathways for studying pigmentation and pigment cell diseases,” said Dr. William Pavan, co-author of the study and senior investigator in NHGRI’s Genetic Disease Research Branch.

“The paper also provides a foundation for others to investigate the DNA loci and associated genes that play roles in skin cancer susceptibility and the effects of UV radiation.”