Ila birthmark


Ila is a birthmark found amongst Samoan infants, up until the last seventy years. It was initially described in Richard Parkinson's classic text "Thirty Years in the South Seas". The mark is circular in shape, about 10 cm across, and lies just above the buttocks of infants up to the age of six months. It has a faint dark blue color.
The birthmark is apparently homozygous recessive. Nearly all Samoan infants were born with this mark, but any ancestry outside of Samoa, however slight, results in the infant not showing the mark. The birthmark is now very rare in Samoa, and can only be found occasionally on remote islands to the west.