title: Autosomal dominant spastic paraplegias: a review of 89 families resulting from a portuguese survey.
abstract: OBJECTIVE
  Hereditary spastic paraplegias (HSPs) are a group of diseases caused by corticospinal tract degeneration. Mutations in 3 genes (SPG4, SPG3, and SPG31) are said to be the cause in half of the autosomal dominant HSPs (AD-HSPs). This study is a systematic review of families with HSP resulting from a population-based survey. Novel genotype-phenotype correlations were established.
  
  
  OBJECTIVE
  To describe the clinical, genetic, and epidemiological features of Portuguese AD-HSP families.
  
  
  METHODS
  Retrospective medical record review.
  
  
  METHODS
  A population-based systematic survey of hereditary ataxias and spastic paraplegias conducted in Portugal from 1993 to 2004.
  
  
  METHODS
  Families with AD-HSP.
  
  
  METHODS
  Mutation detection in the most prevalent genes.
  
  
  RESULTS
  We identified 239 patients belonging to 89 AD-HSP families. The prevalence was 2.4 in 100 000. Thirty-one distinct mutations (26 in SPG4, 4 in SPG3, and 1 in SPG31) segregated in 41% of the families (33.7%, 6.2%, and 1.2% had SPG4, SPG3 and SPG31 mutations, respectively). Seven of the SPG4 mutations were novel, and 7% of all SPG4 mutations were deletions. When disease onset was before the first decade, 31% had SPG4 mutations and 27% had SPG3 mutations. In patients with SPG4 mutations, those with large deletions had the earliest disease onset, followed by those with missense, frameshift, nonsense, and alternative-splicing mutations. Rate of disease progression was not significantly different among patients with SPG3 and SPG4 mutations in a multivariate analysis. For patients with SPG4 mutations, disease progression was worst in patients with later-onset disease.
  
  
  CONCLUSIONS
  The prevalence of AD-HSP and frequency of SPG3 and SPG4 mutations in the current study were similar to what has been described in other studies except that the frequency of SPG4 deletions was lower. In contrast, the frequency of SPG31 mutations in the current study was rare compared with other studies. The most interesting aspects of this study are that even in patients with early-onset disease the probability of finding a SPG4 mutation was higher than for patients with SPG3 mutations; there was no difference in disease progression with genotype but an association with the age at onset; 7 new SPG4 mutations were identified; and for the first time, to our knowledge, the nature of the SPG4 mutations was found to predict the age at onset.
authors: Serviço de Neurologia, Centro Hospitalar entre Douro e Vouga, Rua Dr. Cândido de Pinho, 4520-211 Santa Maria da Feira, Portugal. leal.loureiro@chedv.min-saude.pt
authors: José Leal
authors: JL
authors: Loureiro
authors: Eva
authors: E
authors: Brandão
authors: Luis
authors: L
authors: Ruano
authors: Ana F
authors: AF
authors: Brandão
authors: Ana M
authors: AM
authors: Lopes
authors: Carolina
authors: C
authors: Thieleke-Matos
authors: Leonor
authors: L
authors: Miller-Fleming
authors: Vitor T
authors: VT
authors: Cruz
authors: Mafalda
authors: M
authors: Barbosa
authors: Isabel
authors: I
authors: Silveira
authors: Giovanni
authors: G
authors: Stevanin
authors: Jorge
authors: J
authors: Pinto-Basto
authors: Jorge
authors: J
authors: Sequeiros
authors: Isabel
authors: I
authors: Alonso
authors: Paula
authors: P
authors: Coutinho
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D000328:Adult; D017668:Age of Onset; D001842:Bone and Bones / Q000002:abnormalities; D002386:Cataract / Q000453:epidemiology* / Q000235:genetics*; D004252:DNA Mutational Analysis; D004185:Disability Evaluation; D018450:Disease Progression; D005192:Family Health; D005260:Female; D019204:GTP-Binding Proteins / Q000235:genetics; D005799:Genes, Dominant / Q000235:genetics; D005838:Genotype; D006130:Growth Disorders / Q000453:epidemiology* / Q000235:genetics*; D006306:Health Surveys; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009460:Neurologic Examination; D010641:Phenotype; D011174:Portugal / Q000453:epidemiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015419:Spastic Paraplegia, Hereditary / Q000453:epidemiology* / Q000235:genetics*; D000074181:Spastin; D013223:Statistics as Topic
chemical_list: D008565:Membrane Proteins; C440006:ATL1 protein, human; D000251:Adenosine Triphosphatases; D019204:GTP-Binding Proteins; D000074181:Spastin; C400283:SPAST protein, human