Dihydrolipoamide dehydrogenase deficiency (DLDD) is an inherited disorder caused by lack of the enzyme DLD which provides instructions for the breakdown of three amino acids present in many kinds of foods rich in protein. This leads to a toxic accumulation of these amino acids in the brain and other organs. Symptoms associated with DLDD have variable onset and severity, characterized by recurrent episodes of vomiting, abdominal pain, and brain dysfunction. Affected infants may also have feeding problems, fatigue, seizures, and death may occur soon after birth if the condition is not treated properly. The more severely affected individuals often have some degree of intellectual disability and growth deficiencies. Individuals with the more mild form of DLDD may only show symptoms of liver injury or failure, with no intellectual disability or neurologic deficit. Symptoms arise anytime from infancy into adulthood. There is currently no cure for DLDD, but efforts can be taken to alleviate the symptoms, including dietary restriction of the amino acids that cannot be broken down. However, dietary modifications may not always be effective. This deficiency is caused by pathogenic variants in the DLD gene.