The Effect of Dietary Management and Cysteine Supplementation on Growth Parameters and Biochemical Control for Pediatric Qatari Patients Affected with Classical B6 Non-responsive Homocystinuria.

Cysteine supplementation would be given according to the 2001 ROSS guidelines for the HCU. Cys amino acid supplements are available in the form of powder, each sachet containing 4gm which provides 500mg of Cys per sachet that is available in HMC medical store from where patients receive the medical formula and food at free of cost. The dosage of cysteine will be calculated according to the weight of the patient with the age specific recommendation and prescribed by the metabolic dietitian which will be approved by the metabolic physician prior to the supply of cysteine supplements to the patients. It is not known to have any serious adverse events that is life threatening. A single arm interventional study is opted as the intervention involves all the participants without withholding the treatment. Moreover, a single arm interventional study on cysteine supplementation aims to provide evidence on its efficacy contributing to the advancement of clinical practice in HCU management.