title: Frequency of the LRRK2 G2019S mutation in siblings with Parkinson's disease.
abstract: BACKGROUND
  Mutations in the LRRK2 gene, the most frequent of which is the G2019S mutation in exon 41, cause familial and sporadic Parkinson's disease (PD) with reduced penetrance.
  
  
  OBJECTIVE
  To assess the frequency of the LRRK2 G2019S mutation in families thought to have autosomal recessive PD (siblings but not their parents were affected) and to determine the clinical features of LRRK2 mutation carriers.
  
  
  METHODS
  We sequenced both strands of exon 41 of the LRKK2 gene in 90 index cases from French and North African families in which PD might have been inherited as a recessive trait. Patients with mutations underwent detailed clinical evaluations.
  
  
  RESULTS
  We found heterozygous G2019S mutations in 1 Algerian and 1 French family (overall relative frequency = 2.2%). Four LRRK2-positive patients had typical PD, but their Mini Mental State Examination (MMSE) scores were lower than those of patients without this mutation.
  
  
  CONCLUSIONS
  The LRRK2 G2019S mutation is as frequent in families with possible autosomal recessive PD (2.2%) as in the sporadic cases published elsewhere (1.9%). The clinical features in the LRRK2-positive patients were those of typical PD, except for lower MMSE scores.
authors.affiliation: INSERM, UMR 679, Neurology and Experimental Therapeutics, Hôpital de la Pitié-Salpêtrière, AP-HP, Faculté de Médecine, Université Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Lesage
authors.forename: Laurence
authors.initials: L
authors.lastname: Leclere
authors.forename: Ebba
authors.initials: E
authors.lastname: Lohmann
authors.forename: Michel
authors.initials: M
authors.lastname: Borg
authors.forename: Merle
authors.initials: M
authors.lastname: Ruberg
authors.forename: Alexandra
authors.initials: A
authors.lastname: Dürr
authors.forename: Alexis
authors.initials: A
authors.lastname: Brice
mesh_terms: D000368:Aged; D004252:DNA Mutational Analysis / Q000379:methods; D005060:Europe / Q000453:epidemiology; D005192:Family Health; D005260:Female; D005998:Glycine / Q000235:genetics*; D006801:Humans; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010300:Parkinson Disease / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012694:Serine / Q000235:genetics*; D035781:Siblings
chemical_list: D012694:Serine; C495280:LRRK2 protein, human; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D017346:Protein Serine-Threonine Kinases; D005998:Glycine