Which disease can lead to severe nutritional and metabolic complications if not treated in infancy?

Maple Syrup Urine Disease (MSUD) is an autosomal recessive metabolic disorder caused by a deficiency in branched-chain alpha-keto acid dehydrogenase, leading to an accumulation of branched-chain amino acids (leucine, isoleucine, and valine) and their corresponding keto acids in the body. If untreated, the elevated levels of these metabolites can cause severe neurological damage, developmental delays, and metabolic crises, especially in infancy.

The risk of neurological harm is particularly acute during the first few months of life, when normal protein metabolism is critical for growth and brain development. Prompt identification through newborn screening, combined with dietary management to restrict the intake of branched-chain amino acids, is essential to avoid these severe complications. Early intervention can significantly improve outcomes and prevent the devastating effects associated with the disease.

Other disorders listed can also have nutritional implications if not treated, but the severity and immediate life-threatening risks associated with MSUD make it especially critical to address during infancy. In contrast, while homocystinuria and phenylketonuria (PKU) can lead to significant health issues if untreated, they typically do not result in the same rapid and severe metabolic crisis caused by MSUD. Alkapton