HTRA1 Gene Linked to Wet Macular Degeneration
Homozygous carriers have at least sevenfold risk for age-related macular degeneration
FRIDAY, Oct. 20 (HealthDay News) -- A variation in the HTRA1 gene increases the risk for wet, or neovascular, age-related macular degeneration (AMD), according to two new genetic studies of Asian and white populations. The reports are available in the Oct. 19 online edition of Science.
Andrew DeWan, of Yale University in New Haven, Conn., and colleagues focused on an Asian cohort. The authors found that having two copies of a single-nucleotide polymorphism (SNP) in HTRA1 conferred an 11.1-fold risk for wet AMD.
In the second study, Zhenglin Yang, M.D., of the University of Utah School of Medicine in Salt Lake City, and colleagues genotyped an AMD-susceptibility locus in 581 whites with the disease, as well as 309 controls, and identified the same SNP. Homozygous carriers had a sevenfold risk for AMD and the authors estimated the population attributable risk for acquiring the allele to be 49.3 percent.
The SNP is found in the promoter region of HTRA1 and increases its expression, facilitating degradation of proteoglycans in the retina. "These findings support a key role for HTRA1 in AMD susceptibility and identify a potential new pathway for AMD pathogenesis," Yang's group concludes.