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Exostoses, multiple, type 2(EXT2)

MedGen UID:
377018
Concept ID:
C1851413
Disease or Syndrome
Synonyms: EXOSTOSES, MULTIPLE, TYPE II; EXT2; Hereditary Multiple Osteochondromatosis, Type II
 
Gene (location): EXT2 (11p11.2)
 
Monarch Initiative: MONDO:0007586
OMIM®: 133701

Disease characteristics

Excerpted from the GeneReview: Hereditary Multiple Osteochondromas
Hereditary multiple osteochondromas (HMO), previously called hereditary multiple exostoses (HME), is characterized by growths of multiple osteochondromas, benign cartilage-capped bone tumors that grow outward from the metaphyses of long bones. Osteochondromas can be associated with a reduction in skeletal growth, bony deformity, restricted joint motion, shortened stature, premature osteoarthrosis, and compression of peripheral nerves. The median age of diagnosis is three years; nearly all affected individuals are diagnosed by age 12 years. The risk for malignant degeneration to osteochondrosarcoma increases with age, although the lifetime risk for malignant degeneration is low (~2%-5%). [from GeneReviews]
Authors:
Wim Wuyts  |  Gregory A Schmale  |  Howard A Chansky, et. al.   view full author information

Additional descriptions

From OMIM
Hereditary multiple exostoses is an autosomal dominant disorder characterized by multiple exostoses most commonly arising from the juxtaepiphyseal region of the long bones. For a general phenotypic description and a discussion of genetic heterogeneity of multiple exostoses, see EXT1 (133700).  http://www.omim.org/entry/133701
From MedlinePlus Genetics
Osteochondromas are typically benign; however, in some instances these tumors become malignant (cancerous). Researchers estimate that people with hereditary multiple osteochondromas have a 1 in 20 to 1 in 200 lifetime risk of developing cancerous osteochondromas (called sarcomas).

Multiple osteochondromas can disrupt bone growth and can cause growth disturbances of the arms, hands, and legs, leading to short stature. Often these problems with bone growth do not affect the right and left limb equally, resulting in uneven limb lengths (limb length discrepancy). Bowing of the forearm or ankle and abnormal development of the hip joints (hip dysplasia) caused by osteochondromas can lead to difficulty walking and general discomfort. Multiple osteochondromas may also result in pain, limited range of joint movement, and pressure on nerves, blood vessels, the spinal cord, and tissues surrounding the osteochondromas.

Hereditary multiple osteochondromas is a condition in which people develop multiple benign (noncancerous) bone tumors called osteochondromas. The number of osteochondromas and the bones on which they are located vary greatly among affected individuals. The osteochondromas are not present at birth, but approximately 96 percent of affected people develop multiple osteochondromas by the time they are 12 years old. Osteochondromas typically form at the end of long bones and on flat bones such as the hip and shoulder blade.  https://medlineplus.gov/genetics/condition/hereditary-multiple-osteochondromas

Clinical features

From HPO
Chondrosarcoma
MedGen UID:
3054
Concept ID:
C0008479
Neoplastic Process
A slowly growing malignant neoplasm derived from cartilage cells.
Genu valgum
MedGen UID:
154364
Concept ID:
C0576093
Anatomical Abnormality
The legs angle inward, such that the knees are close together and the ankles far apart.
Short metacarpal
MedGen UID:
323064
Concept ID:
C1837084
Anatomical Abnormality
Diminished length of one or more metacarpal bones in relation to the others of the same hand or to the contralateral metacarpal.
Madelung-like forearm deformities
MedGen UID:
342004
Concept ID:
C1851419
Finding
Coxa vara
MedGen UID:
1790477
Concept ID:
C5551440
Anatomical Abnormality
Coxa vara includes all forms of decrease of the femoral neck shaft angle (the angle between the neck and the shaft of the femur) to less than 120 degrees.
Short stature
MedGen UID:
87607
Concept ID:
C0349588
Finding
A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).
Cervical myelopathy
MedGen UID:
57691
Concept ID:
C0149645
Disease or Syndrome
Peripheral nerve compression
MedGen UID:
343565
Concept ID:
C1851414
Finding
Multiple congenital exostosis
MedGen UID:
4612
Concept ID:
C0015306
Congenital Abnormality
Hereditary multiple osteochondromas (HMO), previously called hereditary multiple exostoses (HME), is characterized by growths of multiple osteochondromas, benign cartilage-capped bone tumors that grow outward from the metaphyses of long bones. Osteochondromas can be associated with a reduction in skeletal growth, bony deformity, restricted joint motion, shortened stature, premature osteoarthrosis, and compression of peripheral nerves. The median age of diagnosis is three years; nearly all affected individuals are diagnosed by age 12 years. The risk for malignant degeneration to osteochondrosarcoma increases with age, although the lifetime risk for malignant degeneration is low (~2%-5%).
Rib exostoses
MedGen UID:
322689
Concept ID:
C1835579
Finding
Multiple circumscribed bony excrescences located in the ribs.
Pelvic bone exostoses
MedGen UID:
335004
Concept ID:
C1844689
Neoplastic Process
A benign growth the projects outward from the bone surface of the pelvis. Exostoses are capped by cartilage, and arise from a bone that develops from cartilage.
Scapular exostoses
MedGen UID:
377019
Concept ID:
C1851415
Neoplastic Process
The presence of multiple exostoses on the scapula. An exostosis is a benign growth the projects outward from the bone surface. It is capped by cartilage.
Protuberances at ends of long bones
MedGen UID:
342003
Concept ID:
C1851418
Finding
The presence of multiple protuberances (bulges, or knobs) at the ends of the long bones.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  

Professional guidelines

PubMed

Baghdadi S, Arabi H, Farhoud A, Moharrami A, Baghdadi T
J Hand Surg Am 2020 Sep;45(9):876.e1-876.e7. Epub 2020 Apr 3 doi: 10.1016/j.jhsa.2020.02.010. PMID: 32253060
Refsland S, Kozin SH, Zlotolow DA
J Hand Surg Am 2016 Sep;41(9):888-95. Epub 2016 Aug 1 doi: 10.1016/j.jhsa.2016.06.008. PMID: 27491595
Tang ZW, Cao YL, Liu T, Chen T, Zhang XS
Eur J Orthop Surg Traumatol 2013 Jul;23(5):611-8. Epub 2012 Jul 1 doi: 10.1007/s00590-012-1033-9. PMID: 23412166

Recent clinical studies

Etiology

Ostetto F, Lana D, Tuzzato G, Staals E, Donati DM, Bianchi G
Hip Int 2023 Mar;33(2):161-168. Epub 2021 Jun 16 doi: 10.1177/11207000211025051. PMID: 34134547
Lu Y, Canavese F, Lin R, Huang Y, Wu X, Lin B, Chen S
Int Orthop 2022 Dec;46(12):2877-2885. Epub 2022 Sep 10 doi: 10.1007/s00264-022-05551-6. PMID: 36087118
Zhang R, Wang X, Liu S, Ruan H, Xu J, Kang Q
Jt Dis Relat Surg 2022;33(1):40-50. Epub 2022 Mar 28 doi: 10.52312/jdrs.2022.502. PMID: 35361079Free PMC Article
Li Y, Wang Z, Chen M, Cai H
J Orthop Surg Res 2020 Dec 9;15(1):594. doi: 10.1186/s13018-020-02137-z. PMID: 33298090Free PMC Article
Baghdadi S, Arabi H, Farhoud A, Moharrami A, Baghdadi T
J Hand Surg Am 2020 Sep;45(9):876.e1-876.e7. Epub 2020 Apr 3 doi: 10.1016/j.jhsa.2020.02.010. PMID: 32253060

Diagnosis

Komura S, Matsumoto K, Hirakawa A, Akiyama H
J Hand Surg Am 2021 Sep;46(9):815.e1-815.e12. Epub 2021 Feb 26 doi: 10.1016/j.jhsa.2020.12.011. PMID: 33642092
Mitsui T, Kim OH, Hall CM, Offiah A, Johnson D, Jin DK, Toh TH, Soneda S, Keino D, Matsubayashi S, Ishii T, Nishimura G, Hasegawa T
Am J Med Genet A 2014 Oct;164A(10):2529-34. Epub 2014 Jul 10 doi: 10.1002/ajmg.a.36669. PMID: 25044890
Tian C, Yan R, Wen S, Li X, Li T, Cai Z, Li X, Du H, Chen H
PLoS One 2014;9(4):e94848. Epub 2014 Apr 11 doi: 10.1371/journal.pone.0094848. PMID: 24728384Free PMC Article
Hoeger PH, Martinez A, Maerker J, Harper JI
Clin Exp Dermatol 2004 May;29(3):222-30. doi: 10.1111/j.1365-2230.2004.01513.x. PMID: 15115498
Bridge JA, Bhatia PS, Anderson JR, Neff JR
Cancer Genet Cytogenet 1993 Sep;69(2):79-90. doi: 10.1016/0165-4608(93)90080-6. PMID: 8402563

Therapy

Ueda K, Inokoshi M, Kubota K, Yamaga E, Minakuchi S
Clin Oral Investig 2023 Dec 26;28(1):22. doi: 10.1007/s00784-023-05424-1. PMID: 38147161
Ostetto F, Lana D, Tuzzato G, Staals E, Donati DM, Bianchi G
Hip Int 2023 Mar;33(2):161-168. Epub 2021 Jun 16 doi: 10.1177/11207000211025051. PMID: 34134547
Lu Y, Canavese F, Lin R, Huang Y, Wu X, Lin B, Chen S
Int Orthop 2022 Dec;46(12):2877-2885. Epub 2022 Sep 10 doi: 10.1007/s00264-022-05551-6. PMID: 36087118
Pacifici M
Bone 2018 Apr;109:267-275. Epub 2017 Aug 19 doi: 10.1016/j.bone.2017.08.010. PMID: 28826842Free PMC Article
Hoeger PH, Martinez A, Maerker J, Harper JI
Clin Exp Dermatol 2004 May;29(3):222-30. doi: 10.1111/j.1365-2230.2004.01513.x. PMID: 15115498

Prognosis

Guo X, Chen S, Lin M, Pan Y, Liu N, Shi T
Genet Test Mol Biomarkers 2021 Jul;25(7):478-485. doi: 10.1089/gtmb.2021.0030. PMID: 34280007
Komura S, Matsumoto K, Hirakawa A, Akiyama H
J Hand Surg Am 2021 Sep;46(9):815.e1-815.e12. Epub 2021 Feb 26 doi: 10.1016/j.jhsa.2020.12.011. PMID: 33642092
Li Y, Wang Z, Chen M, Cai H
J Orthop Surg Res 2020 Dec 9;15(1):594. doi: 10.1186/s13018-020-02137-z. PMID: 33298090Free PMC Article
Tian C, Yan R, Wen S, Li X, Li T, Cai Z, Li X, Du H, Chen H
PLoS One 2014;9(4):e94848. Epub 2014 Apr 11 doi: 10.1371/journal.pone.0094848. PMID: 24728384Free PMC Article
Bridge JA, Bhatia PS, Anderson JR, Neff JR
Cancer Genet Cytogenet 1993 Sep;69(2):79-90. doi: 10.1016/0165-4608(93)90080-6. PMID: 8402563

Clinical prediction guides

Guo X, Chen S, Lin M, Pan Y, Liu N, Shi T
Genet Test Mol Biomarkers 2021 Jul;25(7):478-485. doi: 10.1089/gtmb.2021.0030. PMID: 34280007
Komura S, Matsumoto K, Hirakawa A, Akiyama H
J Hand Surg Am 2021 Sep;46(9):815.e1-815.e12. Epub 2021 Feb 26 doi: 10.1016/j.jhsa.2020.12.011. PMID: 33642092
Michot C, Le Goff C, Blair E, Blanchet P, Capri Y, Gilbert-Dussardier B, Goldenberg A, Henderson A, Isidor B, Kayserili H, Kinning E, Le Merrer M, Lyonnet S, Odent S, Simsek-Kiper PO, Quelin C, Savarirayan R, Simon M, Splitt M, Verhagen JMA, Verloes A, Munnich A, Baujat G, Cormier-Daire V
Eur J Hum Genet 2018 Nov;26(11):1611-1622. Epub 2018 Jul 13 doi: 10.1038/s41431-018-0135-1. PMID: 30006632Free PMC Article
Tian C, Yan R, Wen S, Li X, Li T, Cai Z, Li X, Du H, Chen H
PLoS One 2014;9(4):e94848. Epub 2014 Apr 11 doi: 10.1371/journal.pone.0094848. PMID: 24728384Free PMC Article
Hoeger PH, Martinez A, Maerker J, Harper JI
Clin Exp Dermatol 2004 May;29(3):222-30. doi: 10.1111/j.1365-2230.2004.01513.x. PMID: 15115498

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