Objective: Recent evidence suggests that intermediate-length polyglutamine (PolyQ) expansions in the ataxin-2 (ATXN-2) gene are a risk factor for amyotrophic lateral sclerosis (ALS). This work was undertaken with the aim to investigate the frequency of ataxin-1 (ATXN-1) and ATXN-2 PolyQ expansions in a cohort of patients with sporadic ALS (sALS) and patients with familial ALS (fALS) from southern Italy. Methods: We assessed the PolyQ lengths of ATXN-1 and ATXN-2 in 405 patients with sALS, 13 patients with fALS, and 296 unrelated controls without history of neurodegenerative disorders. Results: We found significantly higher intermediate PolyQ expansions ≥32 for ATXN-1 alleles and ≥28 for ATXN-2 alleles in the sALS cohort (ATXN-1: ALS, 7.07% vs controls, 2.38%; p = 0.0001; ATXN-2: ALS, 2.72% vs controls, 0.5%; p = 0.001). ATXN-1 CAT and ATXN-2 CAA interruptions were detected in patients with ALS only. Age at onset, site of onset, and sex were not significantly related to the ATXN-1 or ATXN-2 PolyQ repeat length expansions. Conclusions: Both ATXN-1 and ATXN-2 PolyQ intermediate expansions are independently associated with an increased risk for ALS.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary cerebrovascular disease leading to accumulating neurologic deficits and dementia. CADASIL has been linked to nucleotide substitutions and deletions in the Notch3 gene. All the mutations described until now lead to unpaired cysteine residue in the epidermal growth factor-like repeats. The authors report a family with CADASIL carrying a deletion in the Notch3 gene that did not involve a cysteine residue.