The aim of this study is to assess the efficacy and safety of betaine in reducing urine oxalate excretion of Type 1 Primary Hyperoxaluria (PHI) patients. Hypothesis: Betaine will effectively reduce urine oxalate excretion in Primary Hyperoxaluria Type I patients.
Name: Betaine
Description: Subjects were randomly assigned oral betaine 12 grams/day in subjects younger than 10 years of age, and 20 grams/day in subjects 10 years of age and older, in two divided doses, for 2 months.Type: DrugBetaine Placebo
Name: Placebo
Description: Subjects received oral lactose placebo, in two doses daily, for 2 months.Type: DrugBetaine Placebo
Description: The patients were randomly assigned oral betaine or placebo for 2 months, followed by a 2 month washout. Each patient then received the alternate study medication for 2 months. Urinary Oxalate Excretion was measured by oxalate oxidase. Two 24 hour urine collections were obtained at baseline, and during the eighth week of each study period.
Measure: Urinary Oxalate Excretion Time: baseline, 2 months, 6 monthsAllocation: Randomized
Crossover Assignment
There is one SNP
Exclusion Criteria: 1. Patients who are fully VB6 responsive (i.e., G170R homozygotes). --- G170R ---
Hyperoxaluria Hyperoxaluria, Primary Our prior genotyping results have shown an association between the G170R allele and the clinical response to VB6. --- G170R ---
Since VB6 is a safe and completely effective treatment for patients homozygous for G170R, we will not study betaine in this group. --- G170R ---
Instead, 20 participants older than 6 years of age who are G170R compound heterozygous, non-G170R missense or truncating sequence change homozygous or heterozygous, will be selected for enrollment. --- G170R ---
Instead, 20 participants older than 6 years of age who are G170R compound heterozygous, non-G170R missense or truncating sequence change homozygous or heterozygous, will be selected for enrollment. --- G170R --- --- G170R ---
Participants in whom VB6 provides a partial reduction in urine oxalate excretion (compound heterozygotes for the G170R mutation) will be maintained on a stable dose of VB6 (8 mg/kg/d) for two months before and throughout betaine treatment. --- G170R ---