Objective: The purpose of this study was to find mutations in the SQSTM1 gene encoding p62 in Japanese patients with amyotrophic lateral sclerosis (ALS), since this gene has been recently identified as a causative gene for familial and sporadic ALS in the United States.
Methods: We sequenced this gene in 61 Japanese patients with sporadic and familial ALS. To our knowledge, we describe for the first time the clinical information of such mutation-positive patients.
Results: We found novel mutations, p.Ala53Thr and p.Pro439Leu, in 2 patients with sporadic ALS. The clinical picture of the mutation-positive patients was that of typical ALS with varied upper motor neuron signs. Although this gene is causative for another disease, Paget disease of bone (PDB), none of our patients showed evidence of concomitant PDB.
Conclusion: The presence of mutations in this racial population suggests worldwide, common involvement of the SQSTM1 gene in ALS.