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.

Summary

Classical homocystinuria (HCU) is an autosomal recessive disorder caused by the deficiency of an enzyme cystathionine β-synthase (CβS) that affects the catabolic pathway of the amino acid methionine (Met) which leads to an accumulation of high levels of methionine and Homocysteine causing complications in the multi system. Therefore, a strict dietary management is crucial to maintain good biochemical control, growth parameters and avoid complications. The main objective would be to analyze the impact of the Met restricted diet on growth parameters, biochemical markers and long-term complications in patients up to 18 years. In addition, the efficacy of dietary management with additional cysteine (Cys) supplementation for the patients up to 18 years would also be examined.

The participants of the study would be recruited from the metabolic and genetics clinic in Hamad General Hospital (HGH), Qatar. All Qatari participants with confirmed diagnosis of HCU \<18 years of age will be included in the study. A mixed method study design would be used which include a cross sectional study design to assess the impact of methionine restricted diet on outcome variables and a single arm interventional study to analyze the effect of additional cysteine supplementation in patients from birth to 18 years. For the retrospective study, all the required data would be retrieved from electronic record from the Cerner of HMC and would be stored in a local drive with password protection. Further, all the eligible participants would be prospectively followed to supplement additional cysteine for the period of 6 months.

The collected data will be statistically analyzed using the "SPSS windows version 22.0 software. The study would improve better understanding of dietary management through the identified outcomes. The outcome of Cys supplementation will improve the protein tolerance, biochemical parameters, growth parameters and may standardize the Cys supplementation.

Conditions

• Classical Homocystinuria

Interventions

DIETARY_SUPPLEMENT

Cysteine

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.

Sponsors & Collaborators

• Hamad Medical Corporation

  lead INDUSTRY

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

1 Day

Max Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-12-01

Primary Completion

2025-07-01

Completion

2025-08-31

Countries

• Qatar

Study Locations