NDP gene
The NDP gene provides instructions for making norrin, a protein essential for the development of the eye and the formation of blood vessels in the retina and inner ear.
Normal Function
The NDP gene provides instructions for making the protein norrin. This protein participates in chemical signaling pathways, including Wnt signaling, which regulates cell division, adhesion, and migration. Norrin binds to frizzled-4 receptors to initiate processes that regulate gene activity. This interaction is crucial for the specialization of retinal cells and the development of blood vessels in the eye and inner ear.
Health Conditions Related to Genetic Changes
Familial exudative vitreoretinopathy
Variants in the NDP gene can cause familial exudative vitreoretinopathy, a disorder that affects the retina and leads to progressive vision loss. These mutations disrupt norrin's ability to bind to frizzled-4, interfering with blood vessel formation at the edges of the retina and causing retinal damage.
Norrie disease
Norrie disease is an inherited disorder caused by NDP gene variants that prevent norrin from binding to frizzled-4. This leads to the accumulation of immature retinal cells and the failure of blood vessel formation in the eye, resulting in blindness in male infants. Because norrin is expressed in other body systems, the condition can also cause intellectual disabilities, seizures, and developmental delays.
Other retinal dystrophies
- Coats disease: Causes leakage of retinal blood vessels and retinal detachment.
- Persistent hyperplastic primary vitreous (PHPV): A condition where a remnant of a fetal blood vessel remains as a fibrous stalk, potentially causing cataracts, glaucoma, or retinal detachment.
- Retinopathy of prematurity: Certain NDP variants have been associated with the worsening of this condition, which involves abnormal blood vessel growth in the retina.
Other Names for This Gene
- ND
- NDP_HUMAN
- Norrie disease (pseudoglioma)
- norrin