The mutation P392L of the sequestosome 1 gene in Paget's disease of bone is frequent in the French population

Background

Paget's disease of bone (PDB) is a chronic disease of the skeleton that affects 3% of the Caucasian population aged over 40 years. PDB often segregates as an autosomal dominant trait. Genetic heterogeneity has been demonstrated, with at least 2 PDB loci, on chromosomes 18 (18q23) and 5 (5q35-qter). At the chromosome 5 locus, (Laurin et al. Am J Hum Genet 2002; 70:1582–1588) identified in the sequestosome 1 (SQSTM1) gene, involved in the RANK (receptor activator of NF-κB) pathway, a recurrent mutation (P392L) present in 16% of the sporadic PDB patients in the French Canadian population. Genetic testing is clinically relevant, as it could lead, in families carrying the mutation, to early diagnosis at the clinically asymptomatic stage, when early treatment could be attempted to prevent complications. However, it is not known whether this mutation is specific to the Cana-dian population or is frequent in other Caucasian populations.

Objective

To evaluate the frequency of the SQSTM1 P392L mutation in the French Caucasian population.

Methods

Nineteen French Caucasian patients with sporadic PDB underwent genetic testing. The search for the mutation relied on a PCR-RFLP assay.

Results

The P392L mutation of SQSTM1 was detected in 2 patients out of 19 (11%).

Conclusion

The P392L mutation of the SQSTM1 gene in PDB is frequent in the French Caucasian population. Investigation of other European populations would be of interest. Genetic testing of PDB patients in France is indicated, aiming at early diagnosis in relatives of patients carrying the mutation.