PURPOSE: For treatment of cystathionine beta-synthase (CbetaS) deficiency, we determined the effect of betaine (N,N,N-trimethylglycine) therapy and examined the genotype-phenotype relationships to betaine. METHODS: In five patients with B6-nonresponsive homocystinuria, we defined the CbetaS genotypes and determined metabolic responses to betaine as an additive to traditional dietary methionine restriction. RESULTS: After betaine therapy, tHcy declined (mean 47.4 micromol/L; range: -21.2 to -104.0 micromol/L; P=0.02), whereas total plasma cysteine and methionine did not change. Plasma methionine/tHcy ratios increased by 5.45 (range: +1.5 to 15.3; P=0.05) inpatients with B6-nonresponsive alleles. CONCLUSION: Betaine improves metabolic control in B6-nonresponsive patients with homocystinuria after optimum dietary control.
PURPOSE: For treatment of cystathionine beta-synthase (CbetaS) deficiency, we determined the effect of betaine (N,N,N-trimethylglycine) therapy and examined the genotype-phenotype relationships to betaine. METHODS: In five patients with B6-nonresponsive homocystinuria, we defined the CbetaS genotypes and determined metabolic responses to betaine as an additive to traditional dietary methionine restriction. RESULTS: After betaine therapy, tHcy declined (mean 47.4 micromol/L; range: -21.2 to -104.0 micromol/L; P=0.02), whereas total plasma cysteine and methionine did not change. Plasma methionine/tHcy ratios increased by 5.45 (range: +1.5 to 15.3; P=0.05) inpatients with B6-nonresponsive alleles. CONCLUSION:Betaine improves metabolic control in B6-nonresponsive patients with homocystinuria after optimum dietary control.
Authors: Andrew A M Morris; Viktor Kožich; Saikat Santra; Generoso Andria; Tawfeg I M Ben-Omran; Anupam B Chakrapani; Ellen Crushell; Mick J Henderson; Michel Hochuli; Martina Huemer; Miriam C H Janssen; Francois Maillot; Philip D Mayne; Jenny McNulty; Tara M Morrison; Helene Ogier; Siobhan O'Sullivan; Markéta Pavlíková; Isabel Tavares de Almeida; Allyson Terry; Sufin Yap; Henk J Blom; Kimberly A Chapman Journal: J Inherit Metab Dis Date: 2016-10-24 Impact factor: 4.982