Novel FUS mutations identified through molecular screening in a large cohort of familial and sporadic amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. Approximately 5%-10% of cases are familial (FALS) and the remaining are sporadic (SALS). To date FUS mutations are responsible for 4%-6% of familial cases as well as 0.7%-1.8% of sporadic cases. METHODS: The frequency of FUS mutations was investigated in an Italian cohort of 500 SALS and 40 FALS patients through direct sequencing of exons 5, 6, 13, 14 and 15. RESULTS: Eight FUS mutation carriers were identified in five SALS (1%) and three FALS (7.5%), five already known and three new mutations: a de novo mutation was identified in a sporadic subject as well as the co-presence of FUS/C9ORF72 mutations in a FALS subject. The molecular and clinical details of the three patients harbouring a novel mutation (G245V, G509D and R491C) are presented here. Moreover the co-presence of the R491C mutation and C9ORF72 pathological expansion was found according to the oligogenic disease model. CONCLUSIONS: In conclusion our results revealed a higher frequency of FUS mutation carriers (7.5%) in FALS compared to literature data together with a higher presence of female gender.

Amyotrophic lateral sclerosis in pregnancy is associated with a vascular endothelial growth factor promoter genotype.

BACKGROUND AND PURPOSE: The occurrence of amyotrophic lateral sclerosis (ALS) during pregnancy is uncommon and the effect of one on the other is not well described. METHODS: The clinical and genetic features of five cases of ALS are reported with an onset during pregnancy or within 1 month from delivery. Charts from 239 women with a diagnosis of ALS attending the neuromuscular clinics at the Neuromuscular Omnicentre (NEMO) and at IRCCS Policlinico San Donato from 2008 to 2011 were reviewed. RESULTS: Of these, 12.8% of the women in child-bearing age had a diagnosis of ALS during pregnancy or immediately after delivery. Genetic screening of the major causative genes revealed two mutations in superoxide dismutase 1 (SOD1) gene; the analysis of vascular endothelial growth factor (VEGF) promoter variation showed a segregation of the haplotype CA/AG (-2578C/A; -1190A/G) in patients developing ALS related to pregnancy. No effects on foetal development or neonatal course were observed. CONCLUSIONS: Pregnancy may unmask ALS but whether this is coincidental is unclear. Hormonal and inflammatory modifications might trigger ALS in subjects with increased susceptibility to oxidative stress related to the toxic function of SOD1 or in subjects with a reduction of neuroprotective molecules such as VEGF.