Active clinical trials for "Homocystinuria"

The purpose of this study is determine if oral N-acetylcysteine is effective in lowering homocysteine in individuals with homocystinuria.

Oral treatment with betaine is conventionally used for patients with inherited homocystinurias. These conditions include a first group of patients with a cystathionine β-synthase (CBS) deficiency and a second group of patients with remethylation defects. The aim of betaine therapy is to reduce level of total plasma homocysteine. Daily dosages and rhythm of administration proposed in the literature vary between 100 to 250 mg / kg / d in 2 to 4 doses. These dosages are not based on validated data and several publications mention much higher dosages particularly when total homocysteine is not controlled. These practices may be unnecessary or even detrimental given the fact that high doses of betaine could for example lead to secondary folate deficiency.

The aim of this research project is to compare the effect of an aerobic exercise session in two different populations. Sampling biological material and collecting health-related personal data entails minimal risks and burdens. Participants will be asked to perform 30 minutes of an aerobic exercise on an ergocycle at a fixed power output to correspond to a moderate intensity for a sedentary population.

OBJECTIVES: I. Determine basal and postmethionine plasma homocysteine in patients with premature vascular disease, cystathionine beta-synthase (CBS) or methylenetitrahydrofolate reductase (MTHFR) deficiency, and in obligate heterozygotes for CBS or MTHFR. II. Determine whole-body homocysteine metabolic rates with isotopically-labeled methionine.