Phenotype and genotype analysis in amyotrophic lateral sclerosis with TARDBP gene mutations

Objective: To describe the phenotype and phenotype–genotype correlations in patients with amyotrophic lateral sclerosis (ALS) with TARDBP gene mutations. Methods: French TARDBP + patients with ALS (n = 28) were compared first to 3 cohorts: 737 sporadic ALS (SALS), 192 nonmutated familial ALS (FALS), and 58 SOD1 + FALS, and then to 117 TARDBP + cases from the literature. Genotype–phenotype correlations were studied for the most frequent TARDBP mutations. Results: In TARDBP + patients, onset was earlier ( p = 0.0003), upper limb (UL) onset was predominant ( p = 0.002), and duration was longer ( p = 0.0001) than in patients with SALS. TARDBP + and SOD1 + groups had the longest duration but diverged for site of onset: 64.3% UL onset for TARDBP + and 74.1% on lower limbs for SOD1 + ( p p = 0.02). The type of mutation influenced survival ( p TARDBP super rich glycine-residue domain, was associated with the worst survival (27 months). Conclusion: Differences in phenotype between the groups as well as the differential influence of TARBDP mutations on survival may help physicians in ALS management and allow refining the strategy of genetic diagnosis.