Two of five patients with sporadic PDB had SQSTM1(C1215T) mutations detected in their affected bone but not in their blood samples, indicating a somatic origin of the mutations.
Mutations in the sequestosome1 (SQSTM1) gene cause PDB in about one-third of familial PDB cases and in 2.4-9.3% of nonfamilial PDB cases, with the 1215C-->T (P392L) mutation being the most frequent one.