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LRP5

LRP5

Reviewed January 2013

What is the official name of the LRP5 gene?

The official name of this gene is “low density lipoprotein receptor-related protein 5.”

LRP5 is the gene's official symbol. The LRP5 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 LRP5 gene?

The LRP5 gene provides instructions for making a protein that is embedded in the outer membrane of many types of cells. It is known as a co-receptor because it works with another receptor protein, frizzled-4 (produced from the FZD4 gene), to transmit chemical signals from outside the cell to the cell's nucleus. Frizzled-4 and the LRP5 protein participate in the Wnt signaling pathway, a series of steps that affect the way cells and tissues develop. Wnt signaling is important for cell division (proliferation), attachment of cells to one another (adhesion), cell movement (migration), and many other cellular activities.

The LRP5 protein plays an important role in the development and maintenance of several tissues. During early development, it helps guide the specialization of cells in the retina, which is the light-sensitive tissue at the back of the eye. The LRP5 protein is also involved in establishing a blood supply to the retina and the inner ear. Additionally, this protein helps regulate bone mineral density, which is a measure of the amount of calcium and other minerals in bones. The minerals give the bones strength, making them less likely to break.

How are changes in the LRP5 gene related to health conditions?

familial exudative vitreoretinopathy - caused by mutations in the LRP5 gene

More than 15 mutations in the LRP5 gene have been identified in people with the eye disease familial exudative vitreoretinopathy. Some of these mutations change single protein building blocks (amino acids) in the LRP5 protein, while others insert or delete genetic material in the gene. Most of these mutations reduce the amount of functional LRP5 protein that is produced within cells.

A reduction in the amount of LRP5 protein disrupts chemical signaling in the developing eye, which interferes with the formation of blood vessels at the edges of the retina. The resulting abnormal blood supply to this tissue can lead to retinal damage and vision loss. Because the LRP5 protein plays a role in bone formation, LRP5 gene mutations also cause reduced bone mineral density in some people with familial exudative vitreoretinopathy.

juvenile primary osteoporosis - caused by mutations in the LRP5 gene

At least five LRP5 gene mutations have been found in people with juvenile primary osteoporosis. Individuals with this condition have low bone mineral density and thinning of the bones (osteoporosis) beginning in childhood. Osteoporosis causes the bones to be brittle and to break easily, which leads to multiple bone fractures. The LRP5 gene mutations that cause this condition result in an LRP5 protein that is unable to transmit chemical signals along the Wnt signaling pathway. The resulting reduction in signaling disrupts regulation of bone mineral density, leading to osteoporosis at a young age.

osteoporosis-pseudoglioma syndrome - caused by mutations in the LRP5 gene

More than 40 LRP5 gene mutations that cause osteoporosis-pseudoglioma syndrome have been identified. Beginning in childhood, people with this condition have extremely low bone mineral density and osteoporosis, which leads to multiple bone fractures. Affected individuals also have eye abnormalities that cause vision impairment from birth or early infancy. Many LRP5 gene mutations that cause osteoporosis-pseudoglioma syndrome prevent cells from making any LRP5 protein. Other mutations change single amino acids in the LRP5 protein. These abnormal proteins cannot insert into the outer membrane of the cell, which makes them unable to perform their function. Loss of LRP5 protein function disrupts the chemical signaling pathways that are needed for the formation of bone and for normal retinal development, leading to the bone and eye abnormalities characteristic of osteoporosis-pseudoglioma syndrome. It is unclear why some LRP5 gene mutations affect eye development and others do not.

other disorders - caused by mutations in the LRP5 gene

Studies suggest that changes in the LRP5 gene may influence the risk of developing osteoporosis in adulthood. Other genetic and environmental factors likely contribute to this common disorder.

Other LRP5 gene mutations cause disorders associated with an increase in bone mineral density. These include autosomal dominant osteopetrosis type 1 and autosomal dominant osteosclerosis. In some cases, these conditions can cause abnormal bone growth and related skeletal abnormalities. Rarely, affected individuals have hearing loss or circulation problems in the brain. Other people with increased bone mineral density do not have any associated health problems. The mutations responsible for increased bone mineral density syndromes overactivate the LRP5 protein, which increases Wnt signaling within cells and enhances bone formation.

Where is the LRP5 gene located?

Cytogenetic Location: 11q13.4

Molecular Location on chromosome 11: base pairs 68,312,608 to 68,449,274

The LRP5 gene is located on the long (q) arm of chromosome 11 at position 13.4.

The LRP5 gene is located on the long (q) arm of chromosome 11 at position 13.4.

More precisely, the LRP5 gene is located from base pair 68,312,608 to base pair 68,449,274 on chromosome 11.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about LRP5?

You and your healthcare professional may find the following resources about LRP5 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 LRP5 gene or gene products?

  • BMND1
  • EVR1
  • EVR4
  • HBM
  • low density lipoprotein receptor-related protein 7
  • LR3
  • LRP5_HUMAN
  • LRP7
  • OPS
  • OPTA1
  • VBCH2

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 LRP5?

acids ; autosomal ; autosomal dominant ; bone formation ; bone mineral density ; calcium ; cell ; cell division ; familial ; gene ; hyperostosis ; juvenile ; lipoprotein ; mineral ; nucleus ; osteoporosis ; proliferation ; protein ; pseudoglioma ; receptor ; retina ; syndrome ; tissue

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (16 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.

 
Reviewed: January 2013
Published: September 15, 2014