title: Effect of leucovorin (folinic acid) on the developmental quotient of children with Down's syndrome (trisomy 21) and influence of thyroid status.
abstract: BACKGROUND
  Seven genes involved in folate metabolism are located on chromosome 21. Previous studies have shown that folate deficiency may contribute to mental retardation in Down's syndrome (DS).
  
  
  METHODS
  We investigated the effect of oral folate supplementation (daily dose of 1.0+/-0.3 mg/kg) on cognitive functions in DS children, aged from 3 to 30 months. They received 1 mg/kg leucovorin or placebo daily, for 12 months, in a single-centre, randomised, double-blind study. Folinic acid (leucovorin, LV) was preferred to folic acid as its bioavailability is higher. The developmental age (DA) of the patients was assessed on the Brunet-Lezine scale, from baseline to the end of treatment.
  
  
  RESULTS
  The intent-to-treat analysis (113 patients) did not show a positive effect of leucovorin treatment. However, it identified important factors influencing treatment effect, such as age, sex, and concomitant treatments, including thyroid treatment in particular. A per protocol analysis was carried out on patients evaluated by the same examiner at the beginning and end of the treatment period. This analysis of 87 patients (43 LV-treated vs. 44 patients on placebo) revealed a positive effect of leucovorin on developmental age (DA). DA was 53.1% the normal value with leucovorin and only 44.1% with placebo (p<0.05). This positive effect of leucovorin was particularly strong in patients receiving concomitant thyroxin treatment (59.5% vs. 41.8%, p<0.05). No adverse event related to leucovorin was observed.
  
  
  CONCLUSIONS
  These results suggest that leucovorin improves the psychomotor development of children with Down's syndrome, at least in some subgroups of the DS population, particularly those on thyroxin treatment.
  
  
  BACKGROUND
  ClinicalTrials.gov, NCT00294593.
authors.affiliation: Institut Jerome Lejeune, Paris, France.
authors.forename: Henri
authors.initials: H
authors.lastname: Blehaut
authors.forename: Clotilde
authors.initials: C
authors.lastname: Mircher
authors.forename: Aimé
authors.initials: A
authors.lastname: Ravel
authors.forename: Martine
authors.initials: M
authors.lastname: Conte
authors.forename: Veronique
authors.initials: V
authors.lastname: de Portzamparc
authors.forename: Gwendael
authors.initials: G
authors.lastname: Poret
authors.forename: Françoise Huon
authors.initials: FH
authors.lastname: de Kermadec
authors.forename: Marie-Odile
authors.initials: MO
authors.lastname: Rethore
authors.forename: Franck G
authors.initials: FG
authors.lastname: Sturtz
mesh_terms: D002675:Child, Preschool; D004311:Double-Blind Method; D004314:Down Syndrome / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D007223:Infant; D002955:Leucovorin / Q000008:administration & dosage*; D008297:Male; D010919:Placebos; D013961:Thyroid Gland / Q000503:physiopathology*
chemical_list: D010919:Placebos; D002955:Leucovorin