Safety and Efficacy Study of Antioxidants for the Treatment of the Fragile X Syndrome
Phase II Double-blind Randomized Placebo-controlled 1-way Crossover Trial to Investigate Safety and Efficacy of the Ascorbic Acid and Tocopherol for the Treatment of the Fragile X Syndrome
  • Phase

    Phase 2
  • Study Type

  • Status

    Completed No Results Posted
  • Intervention/Treatment

    vitamin e vitamin c ...
  • Study Participants

The Fragile X syndrome (FXS) was first described by Dr. Martin and Dr. Bell in 1943, in families with several patients affected by sex-linked mental disability. This disorder is the most common cause of inherited mental disability. The prevalence of the Fragile X syndrome has been established at 1 in 2,500 males and 1 in 4000 females.

Despite moderate to severe mental retardation, fragile X patients exhibit macroorchidism, an elongated face, long ears, connective tissue dysplasia, hyperactivity, autistic-like and stereotypical behaviours, speech delay and increased sensory sensitivity.

Objective: To evaluate the effect of the combination of the antioxidant Ascorbic acid and tocopherol, as therapy of the Fragile X Syndrome in young males.

Hypothesis: It is proposed that part of the pathophysiology of the central nervous system in the animal model of the fragile X syndrome may be determined by oxidative stress. In addition, Fragile X patients showed a significantly low level of ascorbic acid in plasma. The biochemical characteristics of oxidative stress may be reversed in the FMR1-KO mice, by a chronic treatment with antioxidant compounds such as tocopherol or melatonin, it may also normalize several hallmarks of the Syndrome such as hyperactivity, anxiety and cognitive deficits. The normalization of the oxidative stress is proposed as a new therapeutic pathway to alleviate conditions caused by an excess of free radicals that are crucial in neurodevelopmental diseases such as autism, down syndrome and other diseases of the central nervous system.
Objective: To evaluate the effect of the combination of the antioxidant Ascorbic acid and tocopherol, as therapy of the Fragile X Syndrome in young males.
Design: Pilot clinical trial, Phase II , 6-month randomized, double-blind placebo-controlled one-way crossover clinical trial, with two treatment periods of 12 weeks duration.
Setting: IMABIS Foundation. Carlos Haya Hospital, Malaga.
Subjects: Children aged 5-11 years (infants) and 12-18 years (adolescents) diagnosed with Fragile X syndrome.
Intervention: 30 participants randomly assigned, to receive antioxidant vitamins C (ascorbic acid) and vitamin E (d-alpha-tocopherol) once a day or placebo for 12 weeks double-blind. In Study Period 2, all participants receive (open) active treatment. Outcome measures: improvement in plasma antioxidant levels, oxidative stress (indicated by glutathione status, thiobarbituric acid reacting substances (TBARS) and carbonyl content of proteins) and HPA axis response. Behavioral problems will be studied using "Developmental behavior checklist" and "Teacher's and Parent´s Questionnaire, C. Keith Conners", also learning improvement will be analyzed using "Wechsler Intelligence Scale for children" at 0, 3, 6 months during the trial and 3 months after completing the treatment.
Study Started
Dec 31
Primary Completion
Apr 30
Study Completion
Apr 30
Last Update
Apr 14

Dietary Supplement Ascorbic Acid (Vitamin C) and Alpha-tocopherol (Vitamin E)

Vitamin E (D-alpha-Tocopherol) 10 mg/kg/day (with a maximum of 600mg/day) Vitamin C (L-Ascorbic Acid) 10 mg/kg/day (with a maximum of 800mg/day) For 12 weeks

Dietary Supplement Placebo

Two daily dose of placebo, administered at breakfast and dinner for 12 weeks

Ascorbic Acid and alpha-tocopherol Experimental

Two daily doses of the combination of antioxidants, administered at breakfast and dinner

Placebo Placebo Comparator

Two daily doses of placebo, administered at breakfast and dinner


Inclusion Criteria:

Molecular genetics diagnosis of the syndrome (number of CGG repeats in the FMR1 gene over 200).
Presenting characteristic symptoms of fragile X syndrome.
Patients older than 6 years and younger that 19 years.
Signed informed consent by parents and/or legal tutor prior to enrolment in the trial.
Both parents and patients must commit to participate for the duration of the 30 week trial.

Exclusion Criteria:

The study excludes individuals with other neurological disorders not linked to the syndrome.
Patients that have had serious medical problems in the previous 12 months.
Are taking more than 100mg of vitamin E or vitamin C daily for the past 4 months.
Have physical problems, mental or sensory impairments that preclude the assessment of effectiveness.
Hypersensitivity to any component of the preparation.
No Results Posted