Familial Motor Neurone Disease/ALS

Familial Motor Neurone Disease/ Amyotrophic Lateral Sclerosis: identification of new FALS loci and the elucidation of mechanisms of pathogenesis and the provision of an Advisory service for patients and their families. Analysis of gene expression in amyotrophic lateral sclerosis using array technology and tissue expression studies

Amyotrophic lateral sclerosis (ALS) is a late-onset, severe, debilitating condition affecting spinal cord, brain stem and cortical motor neurones causing progressive muscle weakness, atrophy, paralysis and leading finally to respiratory failure. There have been considerable advances in the understanding of disease progression from studies on the dominantly inherited familial form of ALS (FALS) which, although rare, accounting for 5-10% of cases, is clinically indistinguishable from the sporadic form of the disease. Approximately 20% of FALS cases have been shown to be associated with mutations in copper/zinc-dependent superoxide dismutase (SOD1) . A further locus has recently been reported in a single family on chromosome 18q and a family with juvenile-onset autosomal dominant ALS has been mapped to chromosome 9q34 . These are distinct from the rare recessive forms of ALS which map to chromosome 15q15.1-q21.1 and chromosome 2q33 . However, the majority of adult-onset dominantly inherited FALS cases (~80%) can not be attributed to any of these loci and remain to be elucidated. With this as our major goal, we have carried out a genome screen in our most extensive UK families which lack SOD1 mutations. All known loci have been significantly excluded and multiple loci have been indicated in family subsets, one of which shows a significant association with disease (LOD score = +3.5) and lies on chromosome 16.

Key achievements

Establishment of a resource of cases of familial Amyotrophic lateral sclerosis (FALS) and the provision of support for families in the form of a Newsletter, website, telephone “hot line” and Advisory clinic
Extensive SOD1 genotype- phenotype correlation
Genome screen in families lacking SOD1 mutations and the identification of 3 putative FALS loci
Formation of an international consortium to characterise a putative FALS locus on chromosome 16
Extensive characterisation of expressed transcripts in spinal cord using a range of techniques including gridded cDNA arrays and the elucidation of molecular mechanisms of pathogenesis.
Gene identification in Refsum disease .

Future aims

We propose to further characterise previously identified FALS loci, first by refining the regions as much as possible and subsequently by sequencing all genes within the region.

For chromosome 16, this will be carried out in co-operation with the two other members of the consortium to maximise efforts. Initially, candidate genes within the region of overlap between the 4 families linked to chromosome 16 will be sequenced. This region contains approximately 100 known / hypothetical genes and has a physical distance of 5 mega base pairs. Once the disease gene has been identified we propose to:

Characterise expression of the disease gene in control and ALS tissue initially by mRNA analysis and where possible measure functional activity
Express the mutant gene in culture and determine its effect on cell survival and exposure to hypoxic and apoptotic stimuli
Establish transgenic lines expressing the human mutation and determine whether an “mnd” phenotype is developed.
Characterise the molecular and pathological characterisics of this model and determine mechanisms of pathogenesis
Investigate therapeutic approaches using vector mediated gene delivery, RNAi and pharmacological intervention.

Selected Publications.

Clinical and functional investigation of 10 missense mutations and a novel frameshift insertion mutation of the gene for copper-zinc superoxide dismutase in UK families with amyotrophic lateral sclerosis.
Orrell, R.W., Habgood, J,. Gardiner, I., King, A.W., Bowe, F.A., Hallewell, R.A., Marklund, S.L., Greenwood, J., Lane, R.J.M. and de Belleroche, J.
Neurology (1997) 48, 746-751.

Clustering of ALS cases in Central Italy due to occurance of the L84F SOD1 gene mutation
Ceroni M., Malaspina A., Poloni T.E., Alimonti D., Curti D., Rognoni F., Habgood J.J., Imbesi F., Antonelli P., Alfonsi E. and de Belleroche J.S.
Neurology (1999) 53, 1064-71.

Clinical characteristics of SOD1 gene mutatons in UK families with ALS.
Orrell, R.W., Habgood, J.J., Malaspina, A., Mitchell, J., Greenwood J.S.,
Lane, R.J.M. and de Belleroche, J.S.
J Neurol Sci (1999) 169, 56-60

A 14-3-3 mRNA is upregulated in Amyotrophic Lateral Sclerosis (ALS) spinal cord. Malaspina, A., Kaushik, N and de Belleroche, J.S.
J. Neurochem. 2000, 75, 2511-2520.

Identification of genetic heterogeneity in Refsum's disease.
Wierzbicki,A.S., Mitchell J., Lambert-Hammill, M., Margaret Hancock M., Juliet Greenwood J., Sidey M.C., de Belleroche J & Gibberd F.B.
European Journal of Human Genetics (2000) 8, 649 – 651

Differential expression of 14 genes in amyotrophic lateral sclerosis
Malaspina, Andrea, Kaushik, Narendra and de Belleroche Jackie
J. Neurochem. (2001) 77, 132-145.

A survey of trinucleotide/tandem repeat containing transcripts (TNRTs) isolated from human spinal cord to identify genes containing unstable DNA regions as candidates for disorders of motor function.
Malaspina, Andrea, Kaushik, Narendra and de Belleroche Jackie
Brain Research Bulletin : (2001) 56, 299-306.

Neuroprotective effects of copper/zinc-dependent superoxide dismutase against a wide range of death-inducing stimuli and proapoptotic effect of familial amyotrophic lateral sclerosis mutations.
Patel, Y., Collacco-Moraes Y., Latchman, D., Coffin, R. and de Belleroche J.
Molecular Brain Research (2002) 109, 189-197.

Identification of PEX7 as the second gene involved in Refsum disease.
Van den Brink, D.M., Brites, P., Haasjes, J., Wierzbicki, A.S., Mitchell, J., Lambert-Hamil, M., de Belleroche, J., Jansen, G.A., Waterham, H.R. and Wanders, R.J.A.
Am.J.Hum.Genet. (2003) 72, 471-477.

A new familial amyotrophic lateral sclerosis locus on chromosome 16q12.1-16q12.2.
Abalkhail, H. Mitchell, J. Habgood, J. Orrell, R and de Belleroche, J.
Am.J.Hum.Genet. (2003) 73, 383-9.