Paget's disease of bone (PDB) is a common skeletal disorder characterised by increased
bone turnover affecting one or more bones throughout the skeleton. The natural history of
PDB is incompletely understood but it is clear that patients are often asymptomatic when
the disease is at an early stage but that later in life when the patient presents
clinically, irreversible skeletal damage is often present leading to various
complications, some of which are irreversible. The most common symptom of PDB is bone
pain which can be due to increased metabolic activity or complications such as bone
deformity, secondary osteoarthritis, spinal stenosis and pathological fractures. Other
complications include deafness due to involvement of the temporal bone and osteosarcoma
which is rare but often fatal.
Genetic factors play an important role in PDB and people who have a family history of the
disease in a first- degree relative have a seven-times increased risk of developing the
disease as compared with controls. Part of the genetic risk for developing PDB is
explained by inheritance of mutations in the SQSTM1 gene. Cross-sectional studies
indicate that carriers of SQSTM1 mutations run a high risk of developing the disease with
increasing age. However only 40% of people with a family history of PDB carry SQSTM1
mutations and current evidence suggests that the risk of PDB in people who do not carry
SQSTM1 mutations is mediated by inheritance of other susceptibility alleles which
individually have modest effects on the risk of developing PDB but which when combined,
have additive effect on disease susceptibility. Environmental factors also play a role in
PDB and in keeping with this a recent study has shown that epigenetic factors contribute
to the pathogenesis of PDB and may have value as diagnostic markers for the risk of
developing the disease.
It would be highly advantageous to be able to offer people with a family history of PDB a
predictive test to give an indication of their personal risk of PDB. This would allow the
disease to be picked up at an early stage before complications have occurred and for
preventative treatment to be offered. Prevention is key since there is no evidence that
treatment can prevent or reverse complications in people with established disease.
The aim of the present study is to try and identify genetic, epigenetic and other
biomarkers for the development of PDB in people with a family history of the disorder in
order to facilitate early diagnosis and treatment.