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Reviewed February 2009
What is the official name of the NDP gene?
The official name of this gene is “Norrie disease (pseudoglioma).”
NDP is the gene's official symbol. The NDP gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the NDP gene?
The NDP gene provides instructions for making a protein called norrin. Norrin participates in chemical signaling pathways that affect the way cells and tissues develop. Studies suggest that norrin may play a role in Wnt signaling, which is important for cell division (proliferation), attachment of cells to one another (adhesion), cell movement (migration), and many other cellular activities.
Norrin is one of many proteins, or ligands, that can attach (bind) to other proteins called frizzled receptors. These receptors are embedded in the outer membranes of cells. Norrin binds with the receptor frizzled-4 (produced from the FZD4 gene), fitting together like a key in a lock. When a ligand binds to a frizzled receptor, it initiates a multi-step process that regulates the activity of certain genes.
The norrin protein and its receptor frizzled-4 participate in developmental processes that are believed to be crucial for normal development of the eye and other body systems. In particular, norrin seems to play critical roles in the specialization of cells in the retina (the thin layer at the back of the eye that senses light and color) and the establishment of a blood supply to the retina and the inner ear.
Does the NDP gene share characteristics with other genes?
The NDP gene belongs to a family of genes called endogenous ligands (endogenous ligands).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.
How are changes in the NDP gene related to health conditions?
Where is the NDP gene located?
Cytogenetic Location: Xp11.4
Molecular Location on the X chromosome: base pairs 43,948,776 to 43,973,675
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The NDP gene is located on the short (p) arm of the X chromosome at position 11.4.
More precisely, the NDP gene is located from base pair 43,948,776 to base pair 43,973,675 on the X chromosome.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about NDP?
You and your healthcare professional may find the following resources about NDP helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the NDP gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding NDP?
acids ; angiogenesis ; cataract ; cell ; cell division ; cystine ; disability ; expressed ; familial ; gene ; glaucoma ; ligand ; mutation ; optic nerve ; proliferation ; protein ; pseudoglioma ; receptor ; retina ; tissue
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (10 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.