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Renal coloboma syndrome
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Reviewed July 2008
What is renal coloboma syndrome?
Renal coloboma syndrome (also known as papillorenal syndrome) is a condition that primarily affects kidney (renal) and eye development. People with this condition typically have kidneys that are small and underdeveloped (hypoplastic), which can lead to end-stage renal disease (ESRD). This serious disease occurs when the kidneys are no longer able to filter fluids and waste products from the body effectively. It has been estimated that approximately ten percent of children with hypoplastic kidneys may have renal coloboma syndrome. The kidney problems can affect one or both kidneys.
Additionally, people with renal coloboma syndrome may have a malformation in the optic nerve, a structure that carries information from the eye to the brain. Optic nerve malformations are sometimes associated with a gap or hole (coloboma) in the light-sensitive tissue at the back of the eye (the retina). The vision problems caused by these abnormalities can vary depending on the size and location of the malformation. Some people have no visual problems, while others may have severely impaired vision.
Less common features of renal coloboma syndrome include backflow of urine from the bladder (vesicoureteral reflux), multiple kidney cysts, loose joints, and mild hearing loss.
How common is renal coloboma syndrome?
The prevalence of renal coloboma syndrome is unknown; at least 60 cases have been reported in the scientific literature.
What genes are related to renal coloboma syndrome?
Renal coloboma syndrome is caused by mutations in the PAX2 gene. The PAX2 gene provides instructions for making a protein that is involved in the early development of the eyes, ears, brain and spinal cord (central nervous system), kidneys, and genital tract. The PAX2 protein attaches (binds) to specific regions of DNA and regulates the activity of other genes. On the basis of this role, the PAX2 protein is called a transcription factor. After birth, the PAX2 protein is thought to protect against cell death during periods of cellular stress.
Mutations in the PAX2 gene lead to the production of a nonfunctional PAX2 protein that is unable to aid in development, causing incomplete formation of certain tissues. Why the kidneys and eyes are specifically affected by PAX2 gene mutations is unclear.
Approximately half of those affected with renal coloboma syndrome do not have an identified mutation in the PAX2 gene. In these cases, the cause of the disorder is unknown.
Read more about the PAX2 gene.
How do people inherit renal coloboma syndrome?
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
Where can I find information about diagnosis or management of renal coloboma syndrome?
These resources address the diagnosis or management of renal coloboma syndrome and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about renal coloboma syndrome?
You may find the following resources about renal coloboma syndrome helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for renal coloboma syndrome?
What if I still have specific questions about renal coloboma syndrome?
Where can I find general information about genetic conditions?
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 renal coloboma syndrome?
autosomal ; autosomal dominant ; cell ; central nervous system ; cysts ; DNA ; end-stage renal disease ; ESRD ; gene ; inherited ; kidney ; malformation ; mutation ; nervous system ; optic nerve ; prevalence ; protein ; renal ; renal disease ; retina ; stage ; stress ; syndrome ; tissue ; transcription ; transcription factor ; vesicoureteral reflux
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (6 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.