DCUN1D1 is a risk factor for frontotemporal lobar degeneration

BACKGROUND AND PURPOSE: Frontotemporal lobar degeneration (FTLD) is considered as a proteinopathy; therefore, it is conceivable that genes encoding for factors involved in protein misfolding and/or degradation could play a role in its pathogenesis. METHODS: An association study of defective in cullin neddylation 1 (DCN-1)-domain containing 1 (DCUN1D1), which is involved in protein degradation, was carried out in a population of 220 patients with FTLD as compared with 229 age-matched controls. RESULTS: A statistically significant increased frequency of the GG genotype of the DCUN1D1 rs4859146 single nucleotide polymorphism (SNP) was observed in patients compared with controls (6.9 vs. 1.7\%, P = 0.011, adjusted OR: 4.39, 95\% CI: 1.40-13.78). Stratifying according to the clinical syndrome, significant differences were observed between the behavioral variant of frontotemporal dementia and controls (GG frequency: 6.3 vs. 1.7\%, P = 0.02, OR:4.0, 95\%, CI = 1.24-12.92), as well as between patients with progressive aphasia compared with controls (15.4 vs. 1.7\%, P = 0.014, OR = 11.30, 95\%, CI = 1.63-78.45), but not in patients with SD versus controls (8.3 vs. 1.7\%, P = 0.18, OR = 5.24, 95\% C.I. = 0.45-60.63). No significant differences in allelic and genotypic frequencies of the DCUN1D1 rs4859147 SNP were found. CONCLUSIONS: The GG genotype of the DCUN1D1 rs4859147 SNP represents a risk factor for the development of FTLD, increasing the risk of about fourfold.