The protein-based formula provides the infant with the limited amount of BCAAs needed to grow and develop normally. Frequent monitoring of blood levels and adjustments in the formula mixture are necessary to ensure the correct balance of leucine, isoleucine, and valine. As children with MSUD grow, they continue taking the special formula. They are allowed other foods which are weighed or measured in the home to supply the prescribed amount of leucine each day. Typically the MSUD diet does not include any high protein foods such as meat, nuts, eggs, and most dairy products.
Children gradually learn to accept the responsibility for controlling their diets.
There is no age at which diet treatment can be stopped. Lifelong therapy is essential for an optimal outcome. Any common illness or infection can cause elevations in the BCAAs which may precipitate an episode of vomiting, diarrhea, irritability, sleepiness, unusual breathing, staggering, hallucinations, and slurred speech. Left untreated, the child can go into a coma and die. Thus, any signs of illness require initiation of a sick day plan and immediate contact with a health care provider to begin treatment for the illness.