Norrin

Norrin, also known as Norrie disease protein or X-linked exudative vitreoretinopathy 2 protein (EVR2) is a is_associated_with::protein that in humans is encoded by the NDP is_associated_with::gene. Mutations in the NDP gene are associated with the is_associated_with::Norrie disease.

Function
Signaling induced by the protein Norrin regulates is_associated_with::vascular development of vertebrate retina and controls important blood vessels in the ear. Norrin binds with high affinity to Frizzled 4, and Frizzled 4 knockout mice exhibit abnormal vascular development of the retina.

Clinical significance
NDP is the genetic locus identified as harboring mutations that result in Norrie disease. Norrie disease is a rare genetic disorder characterized by bilateral congenital blindness that is caused by a vascularized mass behind each lens due to a maldeveloped retina (pseudoglioma).