Researchers have identified a defective gene that causes myopia, the most common human eye disorder. Led by Ohad Birk, M.D., Ph.D., a research group at the Ben-Gurion University of Negev identified the gene in a thorough study of severe, early-onset myopia that is common in a particular Bedouin tribe in southern Israel. The study results were published in the September 9 issue of the American Journal of Human Genetics.

The gene, LEPREL1, encodes an enzyme that is essential for the final modification of collagen in the eye.

When the active form of this enzyme is absent, aberrant collagen is formed, causing to eyeball to become abnormally elongated. As a result, light beams that enter the eyeball focus in front of the retina rather than on the retina itself.

This distortion leads to the development of myopia. The findings indicate that LEPREL1 plays a significant role in the molecular pathways of ocular growth as well as in the development of both myopia and cataracts.

Future study results will determine whether LEPREL1 or its related genes are associated with ocular abnormalities in a wider population. A better understanding of the molecular causation could allow early diagnosis and treatment, preventing irreversible vision loss, the authors wrote.

Mordechai S, Gradstein L, Pasanen A, et al. High myopia caused by a mutation in LEPREL1, encoding prolyl 3-hydroxylase 2. Am J Hum Genet. 2011 Sep 9;89(3):438-45. Epub Sep 1.