Paget disease of bone is a disorder that causes unusual growth in one or more bones. Affected bones may be weakened, misshapen, and easily broken (fractured).

Paget disease of bone is typically diagnosed in middle age or later. The condition usually affects only one bone or just a few bones and does not spread from one bone to another. Any bones can be affected, although the disease most commonly affects bones in the spine, pelvis, skull, or legs.

Approximately 70 percent of people with Paget disease of bone do not experience any signs or symptoms related to the bone abnormalities. In these individuals, the disease is often diagnosed unexpectedly by x-rays or laboratory tests that are done for other reasons. Pain is the most common symptom reported by people with Paget disease of bone. The affected bones may themselves be painful, or pain may be caused by arthritis in nearby joints. Arthritis occurs when the abnormal bones, particularly weight-bearing bones in the legs, cause extra wear and tear on the joints. Arthritis in the knees and hips is common.

Other signs and symptoms of Paget disease of bone depend on the particular bones that are affected. If the disease affects the bones of the skull, affected individuals may have an enlarged head, hearing loss, headaches, and dizziness. When the condition affects bones in the spine(vertebrae), affected individuals may have an abnormal curvature of the spine or, less commonly, a narrowing of the spinal canal that can put pressure on the spinal cord (spinal stenosis). Spinal stenosis can lead to pain, tingling, and weakness in the legs. When the condition affects the leg bones, these bones may bow and fracture, which can interfere with the ability to walk. 

Some people with Paget disease of the bone have heart or kidney problems. Bone cancer (osteosarcoma) is a rare complication, affecting less than 1 percent of individuals with this condition.

A form of Paget disease that typically develops in childhood, known as juvenile Paget disease, tends to affect multiple bones and has a different pattern of inheritance than Paget disease of bone. 

It is difficult to know exactly how many people have Paget disease of bone, since most affected individuals do not have signs and symptoms of the condition. It is estimated that 1.5 to 8 percent of people in the world have Paget disease of bone. The condition is most common in people of European descent and is rare in people of African and Asian descent.

Research suggests that both the number of cases of Paget disease of bone and the severity of the disorder are decreasing. Although the reasons for these changes are not well-understood, the findings suggest a change in unknown environmental factors.

A combination of genetic and environmental factors likely play a role in the development of Paget disease of bone. Researchers have identified genetic changes that increase the risk of the disorder. Additional factors, including certain viral infections, may help trigger the disease in people who are at an increased risk. However, this theory remains controversial.

Variants (also called mutations) in several different genes have been associated with Paget disease of bone. Most of these genes are involved in bone remodeling, a normal process in which old bone is broken down and new bone is created. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy.

Variants in the SQSTM1 gene are found in as many as 50 percent of affected individuals with a family history of Paget disease of bone and in as many as 10 percent of affected individuals without a family history. The SQSTM1 gene provides instructions for making a protein that helps regulate bone remodeling. The SQSTM1 gene variants that are associated with Paget disease of bone cause cells to produce a protein that does not function properly. The abnormal protein causes an increase in the breakdown of bone, which disrupts the bone remodeling process. As a result, certain bones are broken down and replaced much faster than usual, which leads to the unusually large and misshapen bones seen in people with Paget disease of bone. It is unclear why these problems with bone remodeling affect some bones but not others.

Some people with Paget disease of bone have variants in the SQSTM1 gene that are acquired during a person’s lifetime and are only present in certain cells (somatic). Affected individuals with somatic variants in the SQSTM1 gene tend to have signs and symptoms that are less severe than those seen in people with inherited variants in the SQSTM1 gene.

Genetic Testing Information

• Genetic Testing Registry: Bone Paget disease
• Genetic Testing Registry: Paget disease of bone 4
• Genetic Testing Registry: Paget disease of bone 2, early-onset
• Genetic Testing Registry: Paget disease of bone 3
• Genetic Testing Registry: Paget disease of bone 6

Genetic and Rare Diseases Information Center

• Paget disease of bone, familial

Patient Support and Advocacy Resources

• National Organization for Rare Disorders (NORD)

Clinical Trials

• ClinicalTrials.gov

Catalog of Genes and Diseases from OMIM

• PAGET DISEASE OF BONE 3; PDB3
• PAGET DISEASE OF BONE 2, EARLY-ONSET; PDB2
• PAGET DISEASE OF BONE 4; PDB4
• PAGET DISEASE OF BONE 6; PDB6

Scientific Articles on PubMed

• PubMed

• Banaganapalli B, Fallatah I, Alsubhi F, Shetty PJ, Awan Z, Elango R, Shaik NA. Paget's disease: a review of the epidemiology, etiology, genetics, and treatment. Front Genet. 2023 Apr 26;14:1131182. doi: 10.3389/fgene.2023.1131182. eCollection 2023. Citation on PubMed
• Bouchette P, Boktor SW. Paget Bone Disease. 2023 Nov 12. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK430805/ Citation on PubMed
• Corral Gudino L. Paget's disease of bone: 1877-2023. Etiology, and management of a disease on epidemiologic transition. Med Clin (Barc). 2023 Sep 8;161(5):207-216. doi: 10.1016/j.medcli.2023.05.005. Epub 2023 May 30. English, Spanish. Citation on PubMed
• Gennari L, Rendina D, Merlotti D, Cavati G, Mingiano C, Cosso R, Materozzi M, Pirrotta F, Abate V, Calabrese M, Falchetti A. Update on the pathogenesis and genetics of Paget's disease of bone. Front Cell Dev Biol. 2022 Aug 12;10:932065. doi: 10.3389/fcell.2022.932065. eCollection 2022. Citation on PubMed
• Goode A, Layfield R. Recent advances in understanding the molecular basis of Paget disease of bone. J Clin Pathol. 2010 Mar;63(3):199-203. doi: 10.1136/jcp.2009.064428. Epub 2009 Oct 26. Citation on PubMed
• Maatallah K, Ben Nessib D, Labbene E, Ferjani H, Bouaziz M, Kaffel D, Hamdi W. Paget's Disease of Bone in Patients under 40 Years: Two case reports and review of the literature. Sultan Qaboos Univ Med J. 2021 Feb;21(1):e127-e131. doi: 10.18295/squmj.2021.21.01.019. Epub 2021 Mar 15. Citation on PubMed
• Makaram NS, Ralston SH. Genetic Determinants of Paget's Disease of Bone. Curr Osteoporos Rep. 2021 Jun;19(3):327-337. doi: 10.1007/s11914-021-00676-w. Epub 2021 May 14. Citation on PubMed
• Michou L, Orcel P. Has Paget's bone disease become rare? Joint Bone Spine. 2019 Oct;86(5):538-541. doi: 10.1016/j.jbspin.2019.01.015. Epub 2019 Feb 4. No abstract available. Citation on PubMed
• Ralston SH, Albagha OM. Genetics of Paget's disease of bone. Curr Osteoporos Rep. 2014 Sep;12(3):263-71. doi: 10.1007/s11914-014-0219-y. Citation on PubMed
• Ralston SH, Langston AL, Reid IR. Pathogenesis and management of Paget's disease of bone. Lancet. 2008 Jul 12;372(9633):155-163. doi: 10.1016/S0140-6736(08)61035-1. Citation on PubMed
• Rendina D, Falchetti A, Diacinti D, Bertoldo F, Merlotti D, Giannini S, Cianferotti L, Girasole G, Di Monaco M, Gonnelli S, Malavolta N, Minisola S, Vescini F, Rossini M, Frediani B, Chiodini I, Asciutti F, Gennari L. Diagnosis and treatment of Paget's disease of bone: position paper from the Italian Society of Osteoporosis, Mineral Metabolism and Skeletal Diseases (SIOMMMS). J Endocrinol Invest. 2024 Jun;47(6):1335-1360. doi: 10.1007/s40618-024-02318-1. Epub 2024 Mar 15. Citation on PubMed
• Scotto di Carlo F, Pazzaglia L, Esposito T, Gianfrancesco F. The Loss of Profilin 1 Causes Early Onset Paget's Disease of Bone. J Bone Miner Res. 2020 Aug;35(8):1387-1398. doi: 10.1002/jbmr.3964. Epub 2020 Feb 19. Citation on PubMed
• Singer FR, Bone HG 3rd, Hosking DJ, Lyles KW, Murad MH, Reid IR, Siris ES; Endocrine Society. Paget's disease of bone: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2014 Dec;99(12):4408-22. doi: 10.1210/jc.2014-2910. Citation on PubMed
• Wei Z, Li S, Tao X, Zhu G, Sun Z, Wei Z, Jiao Q, Zhang H, Chen L, Li B, Zhang Z, Yue H. Mutations in Profilin 1 Cause Early-Onset Paget's Disease of Bone With Giant Cell Tumors. J Bone Miner Res. 2021 Jun;36(6):1088-1103. doi: 10.1002/jbmr.4275. Epub 2021 Mar 10. Citation on PubMed
• Whyte MP. Clinical practice. Paget's disease of bone. N Engl J Med. 2006 Aug 10;355(6):593-600. doi: 10.1056/NEJMcp060278. No abstract available. Citation on PubMed