The Role of Inborn Errors of Metabolism in Intellectual Disability

As genetic diagnostic technology advances, clinicians are able to identify more individuals with intellectual disability who have underlying genetic, or in some cases, hereditary forms of disease. Inborn errors of metabolism (metabolic disorders) represent a class of genetic conditions that involve congenital abnormalities in the biochemical processes of the body. The advent of newborn screening in the United States has enabled the fast and accurate detection of many inborn errors that are potentially life-threatening but may still result in significant intellectual disability. Many of these disorders are managed with diet, medications, and in some cases, solid-organ or stem cell transplantation. There are many more metabolic conditions for which available treatment is not readily available or does not yet exist. This chapter will cover many of the most recognizable inborn errors and their role in learning and developmental delay.