Dietary restriction of BCAA is an effective treatment for MSUD. However, intercurrent illness, stress, injury or surgery can trigger a catabolic event leading to increases in plasma and cellular BCAA and their analogous BCKA. Unless immediate intervention with reversal of catabolism and avoidance of cerebral edema are undertaken, patients with MSUD run the risk of damage to their central nervous system that can be manifested in motor, intellectual and/or behavioral impairment. Outcome is therefore dependent on early diagnosis with initiation of treatment, appropriate treatment during catabolic events, and consistent treatment and monitoring to maintain appropriate BCAA levels, growth and health maintenance.

Dietary restriction of the BCAA is complex and requires frequent monitoring and adjustment. Inappropriate intake of medical food can impact growth, nutritional status and overall health. Excessive intake of foods with intact protein can raise BCAA and BCKA levels, cause metabolic decompensation, and have an impact on the central nervous system. Over-restriction of BCAA can impact growth and development and have very specific effects on various tissues of the body. Pregnancy in a woman with MSUD involves not only the typical MSUD management, but also the increased needs of the pregnancy, the health of the fetus, the management of pregnancy-related illnesses and the rapid changes that occur after delivery. Liver transplantation may allow an individual with MSUD to consume a BCAA-unrestricted diet, but without nutritional counseling during the transition, nutrient needs may not be met.

Lack of appropriate nutrition management can result in negative consequences. This can be the result of implementing only some of the recommendations, failing to monitor outcomes, and failing to adjust nutrient intake in response to growth or illness.

• Inappropriate intake of medical food can impact growth and nutritional status and overall health. Excessive intake of foods with intact protein can raise BCAA and BCKA levels, cause metabolic decompensation, and have an impact on the central nervous system.
• Over-restriction of BCAA can impact growth, development and have very specific effects on various tissues of the body.
• Pregnancy in a woman with MSUD involves not only the typical MSUD management, but also the increased needs of the pregnancy, the health of the fetus, the management of pregnancy-related illnesses and the rapid changes that occur after delivery.
• During illness, catabolism increases the endogenous production of BCAA and puts the individual at high risk for metabolic decompensation.
• Liver transplantation may allow an individual with MSUD to consume a BCAA-unrestricted diet, but without nutritional counseling during the transition, nutrient needs may not be met.

Implementing the recommendations would:

• Reduce variations in clinical practice and services across medical centers
• Guide practice decisions that integrate medical and nutrition management/therapy
• Provide clinicians with criteria to make recommendations for nutrition management or recommend other treatments to achieve outcomes
• Design quality nutrition care based on a patient’s metabolic and/or genetic alteration
• Improve patient outcomes and clinician effectiveness
• Enhance patient quality of life, prevent untoward consequences and complications and reduce associated medical, educational and social costs.