Genetic and Functional Analysis of Cherubism

Official title

Identification of Mutations That Lead to Cherubism in Families and Isolated Cases and Studies of Cellular and Molecular Mechanisms

Overview

The goal of this research study is to identify genes and regulatory elements on chromosomes that cause cherubism. Together with the investigators collaborators the investigators also study blood samples and tissue samples from patients to learn about the processes that lead to this disorder. The long-term goal of researchers involved in this study is to find mechanisms to slow down bone resorption in cherubism patients.

Detailed description

Cherubism is a very rare bone disorder where bone gets excessively resorbed only in the jaw bones (mandible and maxilla). The resulting cavities in bone fill up with soft fibrous (fibro-osseous) tissues that can expand and push the bony shells apart. Thus the characteristic facial appearance in patients with progressed cherubism. Bone resorption (cherubism lesions) in this disorder occurs always symmetrically in the mandible, the maxilla or in both. This distinguishes cherubism from similar disorders. As cherubism progresses, the lesions can invade the eye sockets (inferior and/or lateral orbital walls) and displace the eye balls and push down the eyelids. As a result the sclera (white of the eye) below the iris becomes visible and patients have an upward gazing appearance (cherubic look) which gave the name to this fibro-proliferative bone disorder.

Cherubism typically appears between ages of 2-7 years. It is often diagnosed during dental evaluations. At early stages cherubism is accompanied by lymph node swelling. Proliferation of the fibro-osseous tissue typically stops after puberty and in many the soft tissue in the cherubic bone cavities are replaced by new bone.

For this study we will:

* Send out study participation kits and consent by phone * Collect a saliva sample from eligible individuals * Obtain information regarding cherubism * Document disorder with photos and doctor's letters * If patients undergo surgery for cherubism we ask to obtain some bone tissue that would otherwise be discarded * Isolate DNA from the saliva sample * Perform genetic analyses of the DNA with the most up-to-date methods available to identify genetic variations * Study in the laboratory why the genetic variations cause the disorder

Primary outcome measures

• Identification of genetic elements [Time frame: at time of identification]

Eligibility criteria

Inclusion criteria

• cherubism; unaffected individuals only if part of a participating cherubism family

Exclusion criteria

• no cherubism unaffected individuals only as part of a participating cherubism family

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Case-only

Study locations

United States · 1 center

• University of Connecticut Health Center — Farmington

Publications

• Levaot N, Voytyuk O, Dimitriou I, Sircoulomb F, Chandrakumar A, Deckert M, Krzyzanowski PM, Scotter A, Gu S, Janmohamed S, Cong F, Simoncic PD, Ueki Y, La Rose J, Rottapel R. Loss of Tankyrase-mediated destruction of 3BP2 is the underlying pathogenic mechanism of cherubism. Cell. 2011 Dec 9;147(6):1324-39. doi: 10.1016/j.cell.2011.10.045. PMID 22153076
• Ueki Y, Tiziani V, Santanna C, Fukai N, Maulik C, Garfinkle J, Ninomiya C, doAmaral C, Peters H, Habal M, Rhee-Morris L, Doss JB, Kreiborg S, Olsen BR, Reichenberger E. Mutations in the gene encoding c-Abl-binding protein SH3BP2 cause cherubism. Nat Genet. 2001 Jun;28(2):125-6. doi: 10.1038/88832. PMID 11381256
• Gilbert G, Defillo M, Delcan JL, David P. [Results of anastomoses in the tetralogy of Fallot]. Union Med Can. 1966 Dec;95(12):1377-84. No abstract available. French. PMID 5996221
• Ueki Y, Lin CY, Senoo M, Ebihara T, Agata N, Onji M, Saheki Y, Kawai T, Mukherjee PM, Reichenberger E, Olsen BR. Increased myeloid cell responses to M-CSF and RANKL cause bone loss and inflammation in SH3BP2 "cherubism" mice. Cell. 2007 Jan 12;128(1):71-83. doi: 10.1016/j.cell.2006.10.047. PMID 17218256
• Wang CJ, Chen IP, Koczon-Jaremko B, Boskey AL, Ueki Y, Kuhn L, Reichenberger EJ. Pro416Arg cherubism mutation in Sh3bp2 knock-in mice affects osteoblasts and alters bone mineral and matrix properties. Bone. 2010 May;46(5):1306-15. doi: 10.1016/j.bone.2010.01.380. Epub 2010 Feb 1. PMID 20117257
• Levaot N, Simoncic PD, Dimitriou ID, Scotter A, La Rose J, Ng AH, Willett TL, Wang CJ, Janmohamed S, Grynpas M, Reichenberger E, Rottapel R. 3BP2-deficient mice are osteoporotic with impaired osteoblast and osteoclast functions. J Clin Invest. 2011 Aug;121(8):3244-57. doi: 10.1172/JCI45843. Epub 2011 Jul 18. PMID 21765218
• Reichenberger EJ, Levine MA, Olsen BR, Papadaki ME, Lietman SA. The role of SH3BP2 in the pathophysiology of cherubism. Orphanet J Rare Dis. 2012 May 24;7 Suppl 1(Suppl 1):S5. doi: 10.1186/1750-1172-7-S1-S5. Epub 2012 May 24. PMID 22640988
• Papadaki ME, Lietman SA, Levine MA, Olsen BR, Kaban LB, Reichenberger EJ. Cherubism: best clinical practice. Orphanet J Rare Dis. 2012 May 24;7 Suppl 1(Suppl 1):S6. doi: 10.1186/1750-1172-7-S1-S6. Epub 2012 May 24. PMID 22640403

Identifiers

NCT: NCT01630447 · UCHC03-008CBM

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗