Abstract
Disorders of amino acid and nitrogen metabolism (AANMDs) occur due to an enzyme deficiency in a normal biochemical pathway. Nutritional intervention is recognized as the mainstay of treatment for children diagnosed with AANMD. Hence, this scoping review aimed to identify the nutritional interventions available in managing AANMD disorders and their effects on nutritional status. A systematic search using PRISMA Extension for Scoping Reviews (PRISMA-ScR) method was conducted across 4 databases: PubMed, ScienceDirect (Elsevier), EBSCOhost and Cochrane Central Register of Controlled Trials (CENTRAL). Inclusion criteria for the study to be selected are: subjects aged less than 18-year-old, article published in English, utilized an experimental design and published within the past 20 years. A total of 22 articles were included in this review. The majority of the subjects are boys (55.6%) and employed a randomized controlled trial (RCT) study design (45.4%). Nutritional interventions were categorized into 4 categories which are: "protein substitute" (n = 5), "protein substitute with modified composition" (n = 6), "nutrient supplementation (n=8)", and "distribution and dosage of protein substitute (n = 3)". The most frequently assessed outcomes were biochemical parameters that gauge the effectiveness of metabolic control (68.2%). Overall, "protein substitute enriched with inhibitive amino acids", "long-chain polyunsaturated fatty acids supplementation", and "evenly distributed protein substitute" demonstrated beneficial effects towards the nutritional status, especially in terms of biochemical parameters. In summary, nutritional intervention plays a significant role in improving the nutritional status of AANMD patients. Further investigations of nutritional intervention among AANMD children using a meta-analysis approach are necessary for better comprehension of their impact in management of AANMD disorders.