Newborn Screen


Newborn Screen, Newborn Screening

  • Epidemiology
  1. Newborn Screening identifies significant conditions in 5000 to 6000 newborns per year in U.S.
  • Protocol
  • Testing
  1. Testing scope varies by state
    1. Universal Newborn Screening varies by U.S. state
    2. Recommended Uniform Screening Panel (Standardized recommendations for U.S. State screening)
  2. Timing
    1. Before newborn hospital discharge (typically at 24-48 hours of life)
    2. Results are typically available within 24 hours
    3. Consider repeat testing at 1-6 weeks of life (routinely done in 14 states)
  3. Costs
    1. Most states have fee based testing (mean cost $76)
    2. Opt-Out policies are available for parents
  • Labs
  • Standard Core Condition newborn metabolic screening
  1. Amino Acid disorder screening
    1. Homocystinuria (HCY)
    2. Maple syrup urine disease (MSUD)
    3. Classic Phenylketonuria (PKU)
    4. Tyrosinemia Type I (Tyr-1)
  2. Fatty Acid oxidation disorder screening
    1. Carnitine Uptake Defect or carnitine transport defect (CUD)
    2. Medium-chain acyl-CoA dehydrogenase deficiency (MCAD)
    3. Long-chain acyl-CoA dehydrogenase deficiency (LCHAD)
    4. Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD)
    5. Trifunctional Protein deficiency (TFP)
  3. Organic acid disorder screening
    1. 3-methylcrotonyl-CoA carboxylase deficiency (3-MCC)
    2. Beta-ketothiolase deficiency (ßKT)
    3. Glutaric acidemia type I (GA1)
    4. 3-hydroxy-3-methylglutaryl-CoA lyase deficiency or 3-Hydroxy-3-methyglutaric aciduria (HMG)
    5. Isovaleric acidemia (IVA)
    6. Holocarboxylase synthase deficiency or Multiple carboxylase deficiency (MCD)
    7. Propionic acidemia (PROP)
    8. Methylmalonic acidemia
      1. Methylmalonyl-CoA mutase (MUT)
      2. Cobalamin A and B defects (Cbl A, Cbl B)
  4. Urea Cycle Disorder Screening
    1. Argininosuccinic Acidemia or Aciduria (ASA)
    2. Citrullinemia Type 1 (CIT)
  5. Endocrine Disorder Screening
      1. Primary Congenital Hypothyroidism (CH)
    1. Congenital Adrenal Hyperplasia (CAH)
  6. Hemoglobinopathy Screening
    1. Sickle Cell Anemia (Hb SS)
    2. S, ßeta-Thalassemia (Hb S/ßTh )
    3. S,C disease (Hb S/C)
  7. Other Screening
    1. See Newborn Hearing Screening
    2. Biotinidase deficiency (BIOT)
    3. Critical Congenital Heart Disease (CCHD)
    4. Cystic Fibrosis (CF)
      1. Based on Immunoreactive Trypsinogen (IRT) DNA
    5. Classic Galactosemia (GALT)
    6. Glycogen Storage Disease Type II or Pompe Disease (GSD II)
    7. Severe combined Immunodeficiencies (SCID)
    8. Mucopolysaccharidosis Type I (MPS I)
    9. X-linked Adrenoleukodystrophy (X-ALD)
  • Lab
  • Secondary Condition newborn metabolic screening
  1. An addition 26 or more conditions may be detected on Newborn Screening
  • 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)