title: Late-onset spinal motor neuronopathy - a common form of dominant SMA.
abstract: We previously described two Finnish families with a new autosomal dominant late-onset spinal motor neuronopathy that was mapped to chromosome 22q11.2-q13.2. In the current screening study of 43 lower motor neuron disease patients from Finland and Sweden, we identified 26 new late-onset spinal motor neuronopathy patients sharing the founder haplotype. In addition to the main symptoms and signs: painful cramps, fasciculations, areflexia and slowly evolving muscle weakness, new features such as mild bulbar findings, were identified. The disease is relatively benign in terms of life expectancy and rate of disability progression, and it is therefore noteworthy that three patients were initially misdiagnosed with ALS. Significant recombinants in this new patient cohort restricted the disease locus by 90% to 1.8Mb. Late-onset spinal motor neuronopathy seems not to be very rare, at least not in Finland, with 38 patients identified in a preliminary ascertainment.
authors.affiliation: Neuromuscular Research Center, Tampere University and University Hospital, Tampere, Finland. Electronic address: sini.penttila@uta.fi.
authors.forename: Sini
authors.initials: S
authors.lastname: Penttilä
authors.affiliation: Department of Neurology, Turku University Hospital, Turku, Finland. Electronic address: mejoke@utu.fi.
authors.forename: Manu
authors.initials: M
authors.lastname: Jokela
authors.affiliation: Department of Pathology, Fimlab Laboratories, Tampere University Hospital, Tampere, Finland.
authors.forename: Sanna
authors.initials: S
authors.lastname: Huovinen
authors.affiliation: Department of Neurology, Central Hospital of Northern Karelia, Joensuu, Finland.
authors.forename: Anna Maija
authors.initials: AM
authors.lastname: Saukkonen
authors.affiliation: Department of Neurology, Central Hospital of Northern Karelia, Joensuu, Finland.
authors.forename: Jari
authors.initials: J
authors.lastname: Toivanen
authors.affiliation: Neuromuscular Center, Department of Neurology, Sahlgrenska Academy at University Gothenburg, Gothenburg, Sweden.
authors.forename: Christopher
authors.initials: C
authors.lastname: Lindberg
authors.affiliation: Central Hospital of Lapland, Department of Neurology, Rovaniemi, Finland.
authors.forename: Peter
authors.initials: P
authors.lastname: Baumann
authors.affiliation: Neuromuscular Research Center, Tampere University and University Hospital, Tampere, Finland; Department of Neurology, Vasa Central Hospital, Vasa, Finland.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Udd
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D005799:Genes, Dominant; D006801:Humans; D008297:Male; D008875:Middle Aged; D009134:Muscular Atrophy, Spinal / Q000453:epidemiology* / Q000235:genetics* / Q000473:pathology; D010375:Pedigree
keywords: Linkage analysis; Lower motor neuron syndrome; Motor neuron disease