Soragna D, Papi L, Ratti MT, et al. An Italian family affected by Nasu-Hakola disease with a novel genetic mutation in TREM2 gene (J Neurol Neurosurg Psychiatry 2003;74:825–6). The correction in this paper regards the number of the nucleotide of the TREM2 mutation. In the paper the authors wrote that the mutation was at position 191 (191 C→T) in exon 2 of the TREM2 gene. The correct mutation is at position 97 (97 C→T) in exon 2 of the TREM2 gene. The mutation changes glutamine 33 to a stop codon (Q33X); this change is correctly reported in the paper. The authors apologise for the error.