Study of the HFE gene common polymorphisms in French patients with sporadic amyotrophic lateral sclerosis.

International audienceOur objective was to investigate whether the C282Y (p.Cys 282 Tyr) and H63D (p. His 63 Asp) HFE polymorphisms were associated with sporadic amyotrophic lateral sclerosis (SALS) in the French population. We searched for a relation of HFE polymorphisms with the clinical characteristics of the disease. The HFE polymorphisms were studied in 824 patients with SALS and 583 controls. We compared the frequency of the polymorphisms between SALS and controls groups by univariate and multivariate statistics, taking into account gender, site, age-at-onset and survival. We did not observe significant difference in the frequency of H63D polymorphism between SALS and control group. We observed a significant difference for C282Y between patients and controls with a low frequency of the Y allele in patients (3.2%) compared to our control group (5.9%). Disease duration, distribution of gender, site-of-onset, age-at-onset did not differ between groups taking into account genotypes of each polymorphism. Our results in this large cohort of ALS patients indicate that H63D polymorphism is not associated with SALS in the French population. This conclusion does not exclude a weak effect of the HFE gene polymorphisms in certain ALS populations, or an effect of other rare HFE gene variants

Mutations of the ANG gene in French patients with sporadic amyotrophic lateral sclerosis.

International audienceBACKGROUND: Mutations in the angiogenin gene, ANG, have been associated recently with familial and sporadic forms of amyotrophic lateral sclerosis (ALS). However, the cellular and molecular mechanisms that link ANG, a multidomain protein, to ALS are still unknown. OBJECTIVE: To assess the frequency of ANG gene mutations in 855 French patients with sporadic ALS. DESIGN: We analyzed by direct sequencing the full coding region of the ANG gene in a cohort of French patients with sporadic ALS. The clinical characteristics of patients carrying ANG mutations are detailed. SETTING: French ALS Study Group. Patients A total of 855 patients with sporadic ALS. MAIN OUTCOME MEASURES: Results of genetic analyses. RESULTS: We observed a previously identified mutation (pI46V) in 2 patients with ALS without a known family link and found a novel mutation (pR121H) in 1 patient who developed ALS with rapid progression. We did not observe an association between patients with ALS and the rs11701 polymorphism, as previously reported in certain ALS populations of other ethnic origins. CONCLUSION: Overall, our findings support the implication of ANG gene mutations as a rare but widespread cause of ALS

The P413L chromogranin B variation in French patients with sporadic amyotrophic lateral sclerosis.

International audienceChromogranins interact with mutant forms of superoxide dismutase 1 (SOD1) responsible for a portion of familial amyotrophic lateral sclerosis (ALS). A particular variation (P413L) in the chromogranin B gene, CHGB, has been recently associated with an earlier age at onset in both familial and sporadic ALS. The aim of our study was to evaluate the P413L chromogranin variation in French patients with sporadic amyotrophic lateral sclerosis. We developed a High Resolution DNA Melting (HRM) protocol to analyse the P413L variation in the CHGB gene in 540 French patients with sporadic ALS and 504 controls. The clinical characteristics of patients were analysed in relation to their genotype. Results showed that our study on a large cohort of French-Caucasian patients with SALS and controls failed to confirm an increased frequency of the 413L variant in SALS patients. This frequency was 5.3% in the SALS population and 5.5% in the control group. Moreover, we did not observe a previous observation of a difference of age at onset between T-allele carriers and non-carriers (median age of onset 60.4 vs. 62.0 years of age, respectively). Thus, our findings do not support the 413L variant of rs742710 as a risk factor for sporadic ALS in the French population

Association study of the ubiquitin conjugating enzyme gene UBE2H in sporadic ALS.

International audienceUbiquitin inclusions represent a cytopathological hallmark of ALS. The ubiquitin-dependent protein degradation pathway may also be involved in the pathophysiology of SOD1 mutated ALS cases as demonstrated in transgenic animals. UBE2H is an ubiquitin conjugating enzyme known to act on histones and cytoskeletal proteins, both involved in the degenerative pathway of the motor neuron. We screened the whole coding sequence of the UBE2H gene in 24 sporadic ALS (SALS) patients using single strand conformation polymorphism (SSCP). All variants detected by SSCP were analysed by genomic DNA sequencing. We found one known polymorphism (rs12539800) and two new synonymous single nucleotide polymorphisms (SNP) (nG78A and nG501A). The allele distribution of the rs12539800 (A336G) SNP were tested for association in 252 SALS patients and 357 controls. The allele and genotype distributions were identical in the two groups. The UBE2H gene is not implicated in SALS; however, the ubiquitin pathway is worthy of further investigation in ALS

Association between divalent metal transport 1 encoding gene (SLC11A2) and disease duration in amyotrophic lateral sclerosis.

International audienceBACKGROUND: Dysregulation of iron homeostasis is one possible pathophysiological mechanism involved in motor neuron degeneration in amyotrophic lateral sclerosis (ALS). SLC11A2 gene encodes the divalent metal transport 1 (DMT1) mediating iron transport in cerebral endosomal compartments. The objective of the study was to analyze DMT1 as a possible risk or modulating factor in sporadic ALS (SALS). METHODS: We performed a case-control association study on an intronic polymorphism (rs407135) previously analyzed in another neurodegenerative disease, Alzheimer's disease. This polymorphism was studied by DNA sequencing in 579 French patients with SALS and 517 healthy matched individuals. The clinical characteristics of patients were analyzed in relation to their genotypes. RESULTS: We observed that the C allele of rs407135 in SLC11A2 was associated with a shorter disease duration in SALS patients with onset in the legs [Hazard ratio: 1.5 [1.1-2.1] (p=0.02)]. These results are in line with previous observations suggesting that bulbar and spinal motor neurons have different metabolic regulation and gene expression profiles. CONCLUSIONS: Our findings support an implication for iron metabolism in ALS and suggest that the genotype of the SLC11A2 gene could modulate the duration of the disease in French SALS patients