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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®

Otospondylomegaepiphyseal dysplasia

(often shortened to OSMED)
Reviewed July 2008

What is OSMED?

Otospondylomegaepiphyseal dysplasia (OSMED) is a skeletal disorder characterized by skeletal abnormalities, distinctive facial features, and severe hearing loss. The condition involves the ears (oto-), affects the bones of the spine (spondylo-), and enlarges the ends (epiphyses) of long bones in the arms and legs. The features of OSMED are similar to those of another skeletal disorder, Weissenbacher-Zweymüller syndrome.

People with OSMED are often shorter than average because the bones in their legs are unusually short. Other skeletal features include enlarged joints; short arms, hands, and fingers; and flattened bones of the spine (platyspondyly). People with the disorder often experience back and joint pain, limited joint movement, and arthritis that begins early in life.

Severe high-tone hearing loss is common in people with OSMED. Typical facial features include protruding eyes; a flattened bridge of the nose; an upturned nose with a large, rounded tip; and a small lower jaw. Virtually all affected infants are born with an opening in the roof of the mouth (a cleft palate). The skeletal features of OSMED tend to diminish during childhood, but other signs and symptoms, such as hearing loss and joint pain, persist into adulthood.

How common is OSMED?

This condition is rare; the prevalence is unknown. Only a few families with OSMED have been reported worldwide.

What genes are related to OSMED?

Mutations in the COL11A2 gene cause OSMED. The COL11A2 gene is one of several genes that provide instructions for the production of type XI collagen. This type of collagen is important for the normal development of bones and other connective tissues that form the body's supportive framework. Mutations in the COL11A2 gene that cause OSMED disrupt the production or assembly of type XI collagen molecules. The loss of type XI collagen prevents bones and other connective tissues from developing properly.

Related Gene(s)

Changes in this gene are associated with otospondylomegaepiphyseal dysplasia.

  • COL11A2

How do people inherit OSMED?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of OSMED?

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

  • Genetic Testing Registry: Otospondylomegaepiphyseal dysplasia (

You might also find information on the diagnosis or management of OSMED in Educational resources and Patient support.

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 OSMED?

You may find the following resources about OSMED 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 OSMED?

  • Chondrodystrophy with sensorineural deafness
  • Insley-Astley syndrome
  • Mega-epiphyseal dwarfism
  • Nance-Insley syndrome
  • Nance-Sweeney chondrodysplasia
  • Oto-spondylo-megaepiphyseal dysplasia

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines ( and How are genetic conditions and genes named? ( in the Handbook.

What if I still have specific questions about OSMED?

Ask the Genetic and Rare Diseases Information Center (

What glossary definitions help with understanding OSMED?

arthritis ; autosomal ; autosomal recessive ; cell ; cleft palate ; collagen ; dwarfism ; dysplasia ; gene ; inherited ; joint ; lower jaw ; palate ; prevalence ; recessive ; sensorineural ; syndrome

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


  • Melkoniemi M, Brunner HG, Manouvrier S, Hennekam R, Superti-Furga A, Kääriäinen H, Pauli RM, van Essen T, Warman ML, Bonaventure J, Miny P, Ala-Kokko L. Autosomal recessive disorder otospondylomegaepiphyseal dysplasia is associated with loss-of-function mutations in the COL11A2 gene. Am J Hum Genet. 2000 Feb;66(2):368-77. (
  • Temtamy SA, Männikkö M, Abdel-Salam GM, Hassan NA, Ala-Kokko L, Afifi HH. Oto-spondylo-megaepiphyseal dysplasia (OSMED): clinical and radiological findings in sibs homozygous for premature stop codon mutation in the COL11A2 gene. Am J Med Genet A. 2006 Jun 1;140(11):1189-95. (
  • van Steensel MA, Buma P, de Waal Malefijt MC, van den Hoogen FH, Brunner HG. Oto- spondylo-megaepiphyseal dysplasia (OSMED): clinical description of three patients homozygous for a missense mutation in the COL11A2 gene. Am J Med Genet. 1997 Jun 13;70(3):315-23. (


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: July 2008
Published: February 1, 2016