Waardenburg syndrome causing blue eyes in Indonesia and Africa. Waardenburg syndrome is a developmental condition where melanocytes fail to migrate to the iris during embryonic development It causes blue eyes along with other traits: heterochromia, white forelocks, facial alterations, and sometimes congenital hearing loss The syndrome clusters tightly within families due to founder effects in small populations
Some blue eyes have a very different origin. Waardenburg syndrome prevents melanocytes from reaching the iris during development. It also causes heterochromia, white forelocks, hearing loss, and facial differences. Buton Island in Indonesia has rates 100x the global average—around 2%. The condition has existed throughout human history for hundreds of thousands of years.
Key Facts
- Waardenburg syndrome is a developmental condition where melanocytes fail to migrate to the iris during embryonic development
- It causes blue eyes along with other traits: heterochromia, white forelocks, facial alterations, and sometimes congenital hearing loss
- The syndrome clusters tightly within families due to founder effects in small populations
- Highest concentrations in Africa are found in Ethiopia, Kenya, and Tanzania
- Buton Island in Indonesia has rates 100 times the global average, maxing out around 2%
- The San people of Southern Africa also show Waardenburg traits
- This is distinct from European blue eye genetics which only affects iris pigmentation
- Waardenburg syndrome has likely occurred throughout human history for hundreds of thousands of years
Source: The "Dazzling Blue Eyes" of Indonesia and Africa Explained by Timeless with Fred Snyder