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Genetics Home Reference: your guide to understanding genetic conditions
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Kniest dysplasia

Reviewed July 2008

What is Kniest dysplasia?

Kniest dysplasia is a disorder of bone growth characterized by short stature (dwarfism) with other skeletal abnormalities and problems with vision and hearing.

People with Kniest dysplasia are born with a short trunk and shortened arms and legs. Adult height ranges from 42 inches to 58 inches. Affected individuals have abnormally large joints that can cause pain and restrict movement, limiting physical activity. These joint problems can also lead to arthritis. Other skeletal features may include a rounded upper back that also curves to the side (kyphoscoliosis), severely flattened bones of the spine (platyspondyly), dumbbell-shaped bones in the arms and legs, long and knobby fingers, and an inward- and upward-turning foot (clubfoot).

Individuals with Kniest dysplasia have a round, flat face with bulging and wide-set eyes. Some affected infants are born with an opening in the roof of the mouth called a cleft palate. Infants may also have breathing problems due to weakness of the windpipe. Severe nearsightedness (myopia) and other eye problems are common in Kniest dysplasia. Some eye problems, such as tearing of the back lining of the eye (retinal detachment), can lead to blindness. Hearing loss resulting from recurrent ear infections is also possible.

How common is Kniest dysplasia?

Kniest dysplasia is a rare condition; the exact incidence is unknown.

What genes are related to Kniest dysplasia?

Kniest dysplasia is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in the clear gel that fills the eyeball (the vitreous) and in cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Type II collagen is essential for the normal development of bones and other connective tissues that form the body's supportive framework.

Most mutations in the COL2A1 gene that cause Kniest dysplasia interfere with the assembly of type II collagen molecules. Abnormal collagen prevents bones and other connective tissues from developing properly, which leads to the signs and symptoms of Kniest dysplasia.

Related Gene(s)

Changes in this gene are associated with Kniest dysplasia.

  • COL2A1

How do people inherit Kniest dysplasia?

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.

Most 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 Kniest dysplasia?

These resources address the diagnosis or management of Kniest dysplasia and may include treatment providers.

  • Genetic Testing Registry: Kniest dysplasia (http://www.ncbi.nlm.nih.gov/gtr/conditions/C0265279)
  • MedlinePlus Encyclopedia: Clubfoot (http://www.nlm.nih.gov/medlineplus/ency/article/001228.htm)
  • MedlinePlus Encyclopedia: Retinal Detachment (http://www.nlm.nih.gov/medlineplus/ency/article/001027.htm)
  • MedlinePlus Encyclopedia: Scoliosis (http://www.nlm.nih.gov/medlineplus/ency/article/001241.htm)

You might also find information on the diagnosis or management of Kniest dysplasia in Educational resources (http://www.ghr.nlm.nih.gov/condition/kniest-dysplasia/show/Educational+resources) and Patient support (http://www.ghr.nlm.nih.gov/condition/kniest-dysplasia/show/Patient+support).

General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).

To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

Where can I find additional information about Kniest dysplasia?

You may find the following resources about Kniest dysplasia helpful. These materials are written for the general public.

  • MedlinePlus - Health information

    • Encyclopedia: Clubfoot (http://www.nlm.nih.gov/medlineplus/ency/article/001228.htm)
    • Encyclopedia: Retinal Detachment (http://www.nlm.nih.gov/medlineplus/ency/article/001027.htm)
    • Encyclopedia: Scoliosis (http://www.nlm.nih.gov/medlineplus/ency/article/001241.htm)
    • Health Topic: Bone Diseases (http://www.nlm.nih.gov/medlineplus/bonediseases.html)
    • Health Topic: Connective Tissue Disorders (http://www.nlm.nih.gov/medlineplus/connectivetissuedisorders.html)
    • Health Topic: Dwarfism (http://www.nlm.nih.gov/medlineplus/dwarfism.html)
  • Additional NIH Resources - National Institutes of Health
    National Institute of Arthritis and Musculoskeletal and Skin Diseases (http://www.niams.nih.gov/Health_Info/Connective_Tissue/)

  • Educational resources - Information pages

    • Nemours Foundation (http://www.nemours.org/service/medical/skeletaldysplasia/kniest.html)
    • Orphanet (http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=485)

  • Patient support - For patients and families

    • Cleft Palate Foundation (http://www.cleftline.org/)
    • Family Village (http://www.familyvillage.wisc.edu/lib_grow.htm)
    • Human Growth Foundation (http://www.hgfound.org/)
    • International Skeletal Dysplasia Registry, Cedars-Sinai Medical Center (http://isdr.csmc.edu/)
    • Lighthouse International (http://www.lighthouse.org/)
    • Little People of America (http://www.lpaonline.org/)
    • National Organization for Rare Disorders (NORD) (http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/755/viewAbstract)
    • Resource list from the University of Kansas Medical Center (http://www.kumc.edu/gec/support/skeldysp.html)
    • Self Help for Hard of Hearing People (SHHH) (http://www.hearingloss.org/)
    • The MAGIC Foundation (http://www.magicfoundation.org/)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

  • Genetic Testing Registry - Repository of genetic test information

    • Genetic Testing Registry: Kniest dysplasia (http://www.ncbi.nlm.nih.gov/gtr/conditions/C0265279)
  • PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=((kniest%20dysplasia%5BTIAB%5D)%20OR%20(kniest%20syndrome%5BTIAB%5D))%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%203240%20days%22%5Bdp%5D)
  • OMIM - Genetic disorder catalog (http://omim.org/entry/156550)

What other names do people use for Kniest dysplasia?

  • Kniest chondrodystrophy
  • Kniest syndrome
  • Metatropic dwarfism, type II
  • Metatropic dysplasia type II
  • Swiss cheese cartilage dysplasia

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about Kniest dysplasia?

Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).

What glossary definitions help with understanding Kniest dysplasia?

arthritis ; autosomal ; autosomal dominant ; cartilage ; cell ; cleft palate ; clubfoot ; collagen ; dwarfism ; dysplasia ; gene ; incidence ; joint ; kyphoscoliosis ; myopia ; nearsightedness ; palate ; protein ; short stature ; spectrum ; stature ; syndrome ; tissue

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Canepa, G((Giuseppe)); Maroteaux, Pierre; Pietrogrande, Vincenzo; Dysmorphic syndromes and constitutional diseases of the skeleton; Padova : Piccin, c2001 p917-924.
  • Royce, Peter M; Steinmann, Beat U; Connective tissue and its heritable disorders : molecular, genetic, and medical aspects; 2nd ed.; New York : Wiley-Liss, c2002.
  • Subramanian S, Gamanagatti S, Sinha A, Sampangi R. Kniest syndrome. Indian Pediatr. 2007 Dec;44(12):931-3. (http://www.ncbi.nlm.nih.gov/pubmed/18175850?dopt=Abstract)
  • Wilkin DJ, Artz AS, South S, Lachman RS, Rimoin DL, Wilcox WR, McKusick VA, Stratakis CA, Francomano CA, Cohn DH. Small deletions in the type II collagen triple helix produce kniest dysplasia. Am J Med Genet. 1999 Jul 16;85(2):105-12. (http://www.ncbi.nlm.nih.gov/pubmed/10406661?dopt=Abstract)
  • Yokoyama T, Nakatani S, Murakami A. A case of Kniest dysplasia with retinal detachment and the mutation analysis. Am J Ophthalmol. 2003 Dec;136(6):1186-8. (http://www.ncbi.nlm.nih.gov/pubmed/14644246?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: July 2008
Published: May 20, 2013