Newborn Screen

1. See Also
   1. Inborn Errors of Metabolism
2. Protocol: Testing
   1. Testing scope varies by state
      1. Universal U.S. screening includes all labs below except for states listed below
      2. States with limited screening: AL, AR, KS, NH, OK, PA, WA, WV
      3. States doing all labs except listed: NE (CUD), NC (CUD, TYR-1), OH/TN (TYR-1)
   2. Timing
      1. Before newborn hospital discharge
      2. Consider repeat testing at 1-6 weeks of life (routinely done in 14 states)
3. Labs: Standard newborn metabolic screening
   1. Amino acid and urea cycle disorder screening
      1. Argininosuccinic Acidemia
      2. Citrullinemia
      3. Homocystinuria
      4. Maple syrup urine disease
      5. Phenylketonuria (PKU)
      6. Tyrosinemia Type I (Tyr-1)
   2. Fatty Acid oxidation disorder screening
      1. Carnitine Uptake Defect (CUD)
      2. Long-chain acyl-CoA dehydrogenase deficiency
      3. Medium-chain acyl-CoA dehydrogenase deficiency
      4. Trifunctional protein deficiency
      5. Very long-chain acyl-CoA dehydrogenase deficiency
   3. Organic acid disorder screening
      1. 3-methylcrotonyl-CoA carboxylase deficiency
      2. Beta-ketothiolase deficiency
      3. Cobalamin A and B defects
      4. Glutaric acidemia type I
      5. 3-hydroxy-3-methylglutaryl-CoA lyase deficiency
      6. Isovaleric acidemia
      7. Multiple carboxylase deficiency
      8. Methylmalonic acidemia
      9. Propionic acidemia
   4. Hematologic and Endocrine Disorders
      1. Hemoglobinopathy (Obtain prior to transfusion)
      2. Congenital Hypothyroidism
      3. Adrenal Hyperplasia
      4. Galactosemia
      5. Biotinidase deficiency
      6. Cystic Fibrosis
         1. Based on Immunoreactive Trypsinogen (IRT) DNA
         2. CDC recommends adding this to Newborn Screening
         3. Neff (2005) Am Fam Physician 71:1605-10
4. Interpretation
   1. False positive tests are common (up to 60 false positives for every true positive)
      1. Cut-off values are set low to prevent missing actual cases
   2. Borderline results should be immediately retested
   3. Positive results require immediate evaluation
      1. American College of Medical Genetics ACT sheets guide management (see below)
5. Resources
   1. American College of Medical Genetics ACT sheets
      1. http://www.acmg.net/resources/policies/ACT/condition-analyte-links.htm
   2. New England Consortium of Metabolic Programs NBS protocols
      1. http://www.childrenshospital.org/newenglandconsortium/NBS/NBS_Protocols.html
6. References
   1. (2006) Genet Med 8:1S-252S
   2. Kaye (2006) Pediatrics 118:e934-63
   3. Waisbren (2008) Am Fam Physician 77:987-94