The island of the colourblind
In 1775, the western Pacific island of Pingelap was battered by Typhoon Lengkieki, killing 90% of the population-and many of those who survived the storm died after the ensuing famine. Only a few individuals remained to repopulate the island. One man had a rare mutation which he passed on to his descendants, who by the twentieth century represented a large fraction of the island's population. The mutation led to a condition known as achromatopsia, or total colourblindness, in which affected individuals have a complete inability to distinguish colours and see only in shades of grey. The story of the Pingelapese islanders is recounted in the 1998 book Island of the Colourblind by Oliver Sacks and a BBC documentary of the same title.
A team of researchers arrived on Pingelap in 1969 to start the hunt for the gene mutated in the islanders' achromatopsia. More than 30 years later, a team led by Olof Sundin (of the Johns Hopkins University Medical School) has identified the gene, CNGB3, which encodes an essential component of the eye's photoreceptor apparatus (Nature Genetics, Vol. 25, No. 3, pp. 289-293). In an accompanying News & Views article in the July issue of Nature Medicine (Nature Medicine, Vol. 6, No. 7, pp. 746-747), Val Sheffield (of the University of Iowa) offers a historical perspective on the efforts that led to the identification of the gene.
Dr. Olof Sundin
Johns Hopkins University School of Medicine
Department of Ophthalmology
Telephone: +1 410 955-5214
Fax: +1 410 614-4363
Dr. Val Sheffield
Howard Hughes Medical Institute
University of Iowa
Department of Pediatrics
Iowa City, Iowa
Telephone: +1 319 335-6898
Fax: +1 319 335-7588
(C) Nature Genetics press release.
Nature Genetics, Vol. 25, No. 3
Nature Medicine, Vol. 6, No. 7
Message posted by: Trevor M. D'Souza