ITEMS IN AFP WITH MESH TERM:
Metabolism, Inborn Errors
ABSTRACT: Recent innovations in medical technology have changed newborn screening programs in the United States. The widespread use of tandem mass spectrometry is helping to identify more inborn errors of metabolism. Primary care physicians often are the first to be contacted by state and reference laboratories when neonatal screening detects the possibility of an inborn error of metabolism. Physicians must take immediate steps to evaluate the infant and should be able to access a regional metabolic disorder subspecialty center. Detailed knowledge of biochemical pathways is not necessary to treat patients during the initial evaluation. Nonspecific metabolic abnormalities (e.g., hypoglycemia, metabolic acidosis, hyperammonemia) must be treated urgently even if the specific underlying metabolic disorder is not yet known. Similarly, physicians still must recognize inborn errors of metabolism that are not detected reliably by tandem mass spectrometry and know when to pursue additional diagnostic testing. The early and specific diagnosis of inborn errors of metabolism and prompt initiation of appropriate therapy are still the best determinants of outcome for these patients.
ABSTRACT: Family physicians treat an increasing number of children with metabolic disorders identified through newborn screening, and they are often the first line of defense in responding to an abnormal screening result. How the family physician chooses to interpret information from the screening and what he or she chooses to tell the family affects the parent-child relationship, as well as the infant's medical and developmental outcomes. Family physicians must, therefore, be familiar with the current state of expanded newborn screening to effectively communicate results and formulate interventions. They also must recognize signs of metabolic disorders that may not be detected by newborn screening or that may not be a part of newborn screening in their state. For every infant identified with a metabolic disorder, 12 to 60 additional infants will receive a false-positive screening result. One recommendation for communicating results to parents is to explain what the initial and follow-up findings mean, even if the diagnosis is not confirmed. For infants with true-positive results, long-term follow-up involves regular medical examinations, communication with a metabolic treatment center, and developmental and neuropsychological testing to detect possible associated disorders in time for early intervention. This article provides a description of metabolic disorders included in expanded newborn screening programs; a list of disorders screened for in each state; and resources for obtaining ACTion sheets (guidelines for responding to newborn screening results), fact sheets, and emergency and acute illness protocols.