Betaine treatment of cystathionine β-synthase-deficient homocystinuria; does it work and can it be improved?

etaine treatment of cystathionine β-synthase-deficient homocystinuria; does it work and can it be improved? Review (936) Total Article Views Authors: Maclean KN Published Date September 2012 Volume 2012:2 Pages 23 - 33 DOI: http://dx.doi.org/10.2147/ODRR.S27597 Received: 06 July 2012 Accepted: 14 August 2012 Published: 28 September 2012 Kenneth N Maclean Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA Abstract: Inactivating mutations in cystathionine β-synthase result in classical homocystinuria (HCU) and are typically accompanied by severe elevations of plasma and tissue homocysteine, methionine, S-adenosylmethionine, S-adenosylhomocysteine and significantly decreased cysteine. HCU is usually accompanied by marfanoid skeletal abnormalities, osteoporosis, ectopia lentis and/or severe myopia, cognitive impairment, and a dramatically increased incidence of atherosclerosis and thromboembolic complications of variable presentation. If untreated, HCU is a serious life-threatening disease. Betaine (N,N,N-trimethylglycine) is a zwitterionic quaternary ammonium compound that can lower homocysteine, S-adenosylmethionine, S-adenosylhomocysteine, and increase cysteine in HCU by serving as a methyl donor for the remethylation of homocysteine in a reaction catalyzed by betaine–homocysteine S-methyltransferase. This review considers the clinical efficacy and safety of betaine treatment of HCU. Possible strategies by which the efficacy of this treatment might be improved are discussed.