Inborn Errors of Metabolism
A small percentage of sudden infant deaths are attributed to a genetic disorder of metabolism. These disorders are primarily a result of impairments of the b-oxidation of fatty acids and metabolism of organic acids. MCAD (Medium Chain Acyl-CoA dehydrogenase) deficiency is the most common of these inborn errors with a frequency of approximately 1:16,000 in the general population. Nearly one quarter of infants with MCAD deficiency will die suddenly. Approximately 35% will be hospitalized because of hypoglycemia, vomiting, lethargy, seizures and coma. The remainder may be at significant risk for developmental disability and chronic illness. PerkinElmer Genetics' Laboratory can screen for:
Congenital Adrenal Hyperplasia, Methymalonic Acidemias, Propionic Acidemia, Isovaleric Acidemia, Glutaric Acidemia Type I and over 10 other inborn errors in organic acid and fatty acid metabolism on a filter paper dried blood spot. The battery of tests involves the analysis of the enzymes, acylcarnitines, and hormones associated with the conditions listed. Various methodologies are employed including fluorescent and colormetric non-radioactive fully automated immunoassays, molecular analyses, and electrospray tandem mass spectrometry.
Testing & Screening
Historically, the diagnosis of these diseases was achieved through costly urine organic acid analysis. A highly accurate, low cost screening method is available to diagnose both fatty acid and organic acid metabolic disorders in the blood of infants. The method, know as tandem mass spectrometry, obtains a metabolic profile of fatty and organic acids bound to Carnitine, (Acylcarnitine profile), which easily detects these disorders in the blood of affected newborn infants and older children. This technology is also useful in screening autopsy blood samples for explaining suspected or unknown causes of death attributed to inborn errors of metabolism. Table 1 lists the screening frequencies of disorders found in the analysis of more than 7,058 autopsy specimens. 
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