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Genetic and Rare Diseases Information Center (GARD)

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X-linked congenital stationary night blindness


Other Names for this Disease

  • Congenital stationary night blindness with myopia
  • Hemeralopia-myopia
  • Myopia-night blindness
  • X-linked CSNB
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

I have peripheral vision loss, but not night blindness. After a retinal exam, my doctor told me that I have retinitis pigmentosa (RP). Is X-linked congenital stationary night blindness (XLCSNB) a form of RP or a completely different disease? I read that in the incomplete form of XLCSNB, the damage is stationary and the patient may not have night blindness. Is it possible that I am in this group? 

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

How can I find a genetics professional in my area?

Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about genetic consultations is available from Genetics Home Reference. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.

The following online resources can help you find a genetics professional in your community:
Last updated: 6/5/2014

What is X-linked congenital stationary night blindness?

X-linked congenital stationary night blindness (XLCSNB) is a disorder of the retina. People with this condition typically experience night blindness and other vision problems, including loss of sharpness (reduced visual acuity), severe nearsightedness (myopia), nystagmus, and strabismus. Color vision is typically not affected. These vision problems are usually evident at birth, but tend to be stable (stationary) over time. There are two major types of XLCSNB: the complete form and the incomplete form. Both types have very similar signs and symptoms. However, everyone with the complete form has night blindness, while not all people with the incomplete form have night blindness. The types are distinguished by their genetic cause.[1]
Last updated: 10/14/2011

What is retinitis pigmentosa?

Retinitis pigmentosa (RP) is the name given to a group of inherited eye diseases that affect the light-sensitive part of the eye (retina). RP causes cells in the retina to breakdown and die, eventually resulting in vision loss. The first sign of RP is usually night blindness. As the condition progresses, affected individuals also develop tunnel vision. Sometimes RP occurs by itself (isolated RP), and other times it occurs with additional signs and symptoms (syndromic RP). Mutations in at least 50 genes have been found to cause RP. There is no cure for RP, however, there are a few treatment options to slow down the progression of the disease. These options include light avoidance, use of low-vision aids, and vitamin A supplementation.[2]
Last updated: 10/14/2011

Is X-linked congenital stationary night blindness is a form of retinitis pigmentosa?

No, X-linked congenital stationary night blindness and retinitis pigmentosa are separate conditions. Although both RP and XLCSNB can cause night blindness, those with XLCSNB usually do not experience progressive night blindness as seen in those with RP. Furthermore, individuals with the incomplete form of XLCSNB may not experience night blindness at all.[1][3]

Measuring the retina's electrical response to flashes of light is the best way to distinguish the early stages of progressive retinal degeneration (as seen in RP) from non-progressive retinal diseases (such as XLCSNB). This noninvasive instrument, called the electroretinogram, can be used to differentiate RP from XLCSNB.[3]
Last updated: 10/14/2011

Is genetic testing available for X-linked congenital stationary night blindness?

Yes. About 45% of individuals with XLCSNB have the complete form, which is caused by mutations in the NYX gene. The other 55% have the incomplete form, which is caused by mutations in the CACNA1F gene.[4] GeneTests lists the names of laboratories that are performing genetic testing for both of these genes. To view the contact information for the clinical laboratories conducting testing for NYX, click here. To view the contact information for the clinical laboratories conducting testing for CACNA1F, click here

Please note:  Most of the laboratories listed through GeneTests do not accept direct contact from patients and their families; therefore, if you are interested in learning more, you will need to work with a health care provider or a genetics professional.  In the Services tab, we provide a list of online resources that can assist you in locating a genetics professional near you.
Last updated: 10/14/2011

References
Other Names for this Disease
  • Congenital stationary night blindness with myopia
  • Hemeralopia-myopia
  • Myopia-night blindness
  • X-linked CSNB
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.