Clinical characteristics of patients with familial amyotrophic lateral sclerosis carrying the pathogenic GGGGCC hexanucleotide repeat expansion of C9ORF72

A large hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72, a gene located on chromosome 9p21, has been recently reported to be responsible for similar to 40% of familial amyotrophic lateral sclerosis cases of European ancestry. The aim of the current article was to describe the phenotype of amyotrophic lateral sclerosis cases carrying the expansion by providing a detailed clinical description of affected cases from representative multi-generational kindreds, and by analysing the age of onset, gender ratio and survival in a large cohort of patients with familial amyotrophic lateral sclerosis. We collected DNA and analysed phenotype data for 141 index Italian familial amyotrophic lateral sclerosis cases (21 of Sardinian ancestry) and 41 German index familial amyotrophic lateral sclerosis cases. Pathogenic repeat expansions were detected in 45 (37.5%) patients from mainland Italy, 12 (57.1%) patients of Sardinian ancestry and nine (22.0%) of the 41 German index familial amyotrophic lateral sclerosis cases. The disease was maternally transmitted in 27 (49.1%) pedigrees and paternally transmitted in 28 (50.9%) pedigrees (P = non-significant). On average, children developed disease 7.0 years earlier than their parents [children: 55.8 years (standard deviation 7.9), parents: 62.8 (standard deviation 10.9); P = 0.003]. Parental phenotype influenced the type of clinical symptoms manifested by the child: of the 13 cases where the affected parent had an amyotrophic lateral sclerosis-frontotemporal dementia or frontotemporal dementia, the affected child also developed amyotrophic lateral sclerosis-frontotemporal dementia in nine cases. When compared with patients carrying mutations of other amyotrophic lateral sclerosis-related genes, those with C9ORF72 expansion had commonly a bulbar onset (42.2% compared with 25.0% among non-C9ORF72 expansion cases, P = 0.03) and cognitive impairment (46.7% compared with 9.1% among non-C9ORF72 expansion cases, P = 0.0001). Median survival from symptom onset among cases carrying C9ORF72 repeat expansion was 3.2 years lower than that of patients carrying TARDBP mutations (5.0 years; 95% confidence interval: 3.6-7.2) and longer than those with FUS mutations (1.9 years; 95% confidence interval: 1.7-2.1). We conclude that C9ORF72 hexanucleotide repeat expansions were the most frequent mutation in our large cohort of patients with familial amyotrophic lateral sclerosis of Italian, Sardinian and German ancestry. Together with mutation of SOD1, TARDBP and FUS, mutations of C9ORF72 account for similar to 60% of familial amyotrophic lateral sclerosis in Italy. Patients with C9ORF72 hexanucleotide repeat expansions present some phenotypic differences compared with patients with mutations of other genes or with unknown mutations, namely a high incidence of bulbar-onset disease and comorbidity with frontotemporal dementia. Their pedigrees typically display a high frequency of cases with pure frontotemporal dementia, widening the concept of familial amyotrophic lateral sclerosis

Analysis of the (CAG)n Repeat at the IT15 Locus in a Population from Calabria (Southern Italy)

The defect causing Huntington’s disease (HD) has recently been discovered as an expanded CAG trinucleotide repeat located at the 5\u27 end of the IT 15 gene. This discovery allows the molecular diagnosis of HD by measuring the CAG repeat length. The normal and pathological repeat ranges in a population need to be established before a diagnostic test for HD can be performed. To determine the distribution of IT 15 alleles in a population from Calabria (southern Italy), we analyzed 102 normal subjects and 9 HD patients coming from a defined area of Calabria (province of Cosenza). Expanded alleles ranged from 44 to 76 repeats. Normal alleles varied from 8 to 27 repeats, which is one of the lowest values observed at the top of the normal range; the mean was significantly different from the value observed in six other populations. The allele distribution seemed to group mainly around the mode, and no intermediate alleles were present in our sample. These results suggest a particular stability of the CAG repeat at the IT 15 locus in the Calabrian group and confirm once again the peculiar genetic structure of this population

Supplementary Material for: ALS-Related Mutant FUS Protein Is Mislocalized to Cytoplasm and Is Recruited into Stress Granules of Fibroblasts from Asymptomatic FUS P525L Mutation Carriers

<i>Background:</i> Amyotrophic lateral sclerosis (ALS) shows a strong genetic basis, with <i>SOD1</i>, <i>FUS</i>, <i>TARDBP</i>, and <i>C9ORF72 </i>being the genes most frequently involved<i>. </i>This has allowed identification of asymptomatic mutation carriers, which may be of help in understanding the molecular changes preceding disease onset. <i>Objectives:</i> We studied the cellular expression of FUS protein and the effect of heat-shock- and dithiothreitol-induced stress in fibroblasts from <i>FUS</i> P525L mutation carriers, healthy controls, and patients with sporadic ALS. <i>Methods:</i> Western blots and immunocytochemistry were performed to study the subcellular localization of FUS protein. Control and stressed cells were double stained with FUS and the stress marker TIA-R. <i>Results:</i> Fibroblasts from healthy controls and sporadic ALS cases showed a prominent nuclear FUS expression. In the 2 <i>FUS</i> P525L mutation carriers, instead, most cells showed a protein localization in both nucleus and cytoplasm, or exclusively in the cytoplasm. Stress prompted the formation of cytoplasmic granules in all subjects and in sporadic ALS FUS mislocalization to the cytoplasm. Cytoplasmic FUS was recruited into stress granules, which showed a time-dependent decrease in all subjects. However, in the <i>FUS</i> P525L fibroblasts, the granules persisted longer, and they were more numerous than those detected in the cells from controls and sporadic ALS patients. <i>Conclusions:</i> We show that in fibroblasts of <i>FUS</i> P525L mutation carriers, FUS mislocalized to the cytoplasm where it redistributed into stress granules with likely a dose effect, i.e. a higher number of cells with granules, which persist longer, than in controls and ALS cases. These data represent an early molecular change occurring before ALS onset, suggesting a transient preaggregative state

Further evidence of genetic heterogeneity in autosomal dominant distal motor neuronopathy

Distal hereditary motor neuronopathy is a genetically and clinically heterogeneous disorder. To date, five loci, and their relative genes, have been mapped on chromosomes 7p14, 7q11, 9q34, 11q12 and 12q24, respectively. We describe an Italian family with autosomal dominant distal HMN starting at around 30 years of age with weakness and atrophy of distal leg muscles and pyramidal features. We performed genetic linkage analysis on chromosomes 7p14, 9q34, 11q12 and 12q24. Moreover we sequenced the genes mapped to 7q11 and 12q24. Negative LOD scores excluded linkage to 7p14, 9q34, and 11q12 chromosomes in our family. No mutations were found in genes mapped to 7q11 and 12q24. In addition, because of pyramidal features, we performed the linkage analysis to all the known loci for autosomal dominant hereditary spastic paraparesis. The analysis was negative thus excluding a complicated form of autosomal dominant hereditary spastic paraparesis. These data further confirm a genetic heterogeneity within inherited motor neuronopathy

Mutation analysis of the SPG4 gene in Italian patients with pure and complicated forms of spastic paraplegia

Mutations in the SPG4 gene are the most common causes of hereditary spastic paraplegia (HSP) accounting for up to 40% of autosomal dominant (AD) forms and 12-18% of sporadic cases. The phenotype associated with HSP due to mutations in the SPG4 gene tends to be pure. There is increasing evidence, however, of patients with complicated forms of spastic paraplegia in which SPG4 mutations were identified. A cohort of 38 unrelated Italian patients with spastic paraplegia, of which 24 had a clear dominant inheritance and 14 were apparently sporadic, were screened for mutations in the SPG4 gene. We identified 11 different mutations, six of which were novel (p.Glu143GlyfsX8, p.Tyr415X, p.Asp548Asn, c.1656_1664delinsTGACCT, c.1688-3C>G and c.*2G>T) and two exon deletions previously reported. The overall rate of SPG4 gene mutation in our patients was 36.8% (14/38); in AD-HSP we observed a mutation frequency of 45.8% (11/24), in sporadic cases the frequency was 21.4% (3/14). Furthermore, we found a mutational rate of 22.2% (2/9) and 41.4% (12/29) in the complicated and pure forms, respectively. The results underlie the importance of genetic testing in all affected individuals

Narrowing of the critical region in autosomal recessive spastic paraplegia linked to the SPG5 locus

Hereditary spastic paraplegias are neurodegenerative disorders characterized clinically by progressive spasticity of the lower limbs. They are inherited as autosomal dominant, autosomal recessive, and X-linked traits. Four Italian families with autosomal recessive pure spastic paraplegia are reported. We show evidence of linkage to the SPG5 locus on chromosome 8p and our data reduce the candidate interval for SPG5 to the11-cM interval spanned by D8S285 and D8S544. We also report the search for mutations in five genes located in the region and their exclusion as candidates for SPG5

The DELPHI detector at LEP

DELPHI is a 4π detector with emphasis on particle identification, three-dimensional information, high granularity and precise vertex determination. The design criteria, the construction of the detector and the performance during the first year of operation at the large electron positron collider (LEP) at CERN are described. © 1991 - Elsevier Science Publishers B.V. (North-Holland)