Howard Hughes Medical Institute (HHMI) investigator Jeremy Nathans at The Johns Hopkins University School of Medicine led the research team, which published its findings in the March 19, 2004, issue of the journal Cell. Co-lead authors of the article were HHMI associate Qiang Xu and HHMI research specialist Yanshu Wang. Other authors are from the National Institute on Deafness and Other Communication Disorders, the University of Utah, and the Wills Eye Hospital in Philadelphia.
The researchers studied two inherited disorders, Norrie disease and familial exudative vitreoretinopathy (FEVR), whose underlying genetic defects were already known, but whose mechanistic relationship was not. Norrie disease, caused by a defect in the gene for the protein Norrin, produces congenital blindness and a progressive deafness due to blood vessel malformation in the inner ear. "Almost certainly the sequence of events within the eye is that there is a problem in vascular development, a compensatory growth of blood vessels, and a leakiness in those blood vessels that leads to scarring and ultimately blindness," said Nathans. The function of the Norrin protein was unknown before this new work, he said.
The second disorder the researchers studied, FEVR, "tends to be milder and with a range of severity all the way from a modest abnormality of vasculature that does not impair vision at al
Contact: Jim Keeley
Howard Hughes Medical Institute