title: Anticipation of age at onset in familial multiple sclerosis.
abstract: OBJECTIVE
  Anticipation of age at onset in the younger generations is a widely known characteristic of many diseases with genetic inheritance. This study was performed to assess whether there is anticipation of age at onset in younger generations of familial multiple sclerosis (MS) in a Spanish population and to compare clinical characteristics of familial and sporadic MS.
  
  
  METHODS
  We studied a cohort of 1110 patients diagnosed with MS and followed-up in our MS Unit. Patients were considered as familial MS if they had in their family at least one relative of first or second degree diagnosed with MS. Otherwise, patients were considered to have sporadic MS. We compared the age at onset between relatives from different generations, and we also compared the age at onset of familial and sporadic MS.
  
  
  RESULTS
  A lower age at onset in the younger generations was found (median 22 years vs. 30 years, P < 0.001) and a significant lower age at onset of the disease in familial MS comparing to sporadic MS (median 25 years vs. 29 years, P = 0.042).
  
  
  CONCLUSIONS
  There is an anticipation of the age at onset of MS in the younger generations of patients with familial MS. There is also a lower age at onset in familial versus sporadic MS.
authors.affiliation: Neurology Department, Multiple Sclerosis Unit, Hospital Universitari de Bellvitge, IDIBELL, Barcelona, Spain. lromeropinel@gmail.com
authors.forename: L
authors.initials: L
authors.lastname: Romero-Pinel
authors.forename: S
authors.initials: S
authors.lastname: Martínez-Yélamos
authors.forename: L
authors.initials: L
authors.lastname: Gubieras
authors.forename: E
authors.initials: E
authors.lastname: Matas
authors.forename: L
authors.initials: L
authors.lastname: Bau
authors.forename: M
authors.initials: M
authors.lastname: Kremenchutzky
authors.forename: T
authors.initials: T
authors.lastname: Arbizu
mesh_terms: D000328:Adult; D017668:Age of Onset; D020132:Anticipation, Genetic; D015331:Cohort Studies; D016208:Databases, Factual; D005190:Family; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D020528:Multiple Sclerosis, Chronic Progressive / Q000453:epidemiology* / Q000523:psychology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000453:epidemiology* / Q000523:psychology*; D015995:Prevalence; D012042:Registries; D012189:Retrospective Studies; D013030:Spain / Q000453:epidemiology; D055815:Young Adult