More genetic variations linked to AMD risk

Researchers analyzed the association between AMD and polymorphisms in the gene coding for VEGF-A and the VEGF receptor KDR in 226 subjects with AMD plus controls.  They identified two polymorphisms (rs833069 in intron 2 of the VEGF-A gene, rs2071559 in the promoter of the KDR gene) to be significantly associated with risk of AMD. This is the first time a VEGF receptor KDR polymorphism has been linked to AMD.

In the VEGF-A gene, at site rs833069, a guanine substitution increased the risk of AMD fivefold compared with carriage of the adenine allele. At site rs2071559 of the KDR gene, thymine homozygotes carried a greater than threefold increased risk of AMD compared with homozygous carriage of the cytosine allele. In subjects carrying both risk alleles, the risk of AMD was increased greater than sixfold compared with subjects carrying non-risk alleles.

In addition, the site of the thymine substitution on the KDR gene is an area of known high transcription activity, which further supports the role of the VEGF pathway in the pathophysiology of AMD.