It is health that is real wealth
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- Mahatma Gandhi

Newborn Screening ACT Sheet

[Elevated C0/C16+C18]
Carnitine Palmitoyl Transferase 1 Deficiency (CPT1)

Differential Diagnosis: Carnitine palmitoyl transferase 1 deficiency (CPT1).

Condition Description: This disorder is caused by a deficiency of the enzyme CPT1, preventing the fatty acid carnitine- acylcarnitine linkage required to transport fatty acids into the mitochondria. This results in accumulation of free carnitine (C0) and prevents the fatty acid oxidation response necessary to generate energy during fasting and increased energy needs (fever, stress).


  • Contact family to inform them of the newborn screening result and ascertain clinical status (lethargy, seizures).
  • Consult with pediatric metabolic specialist.
  • Evaluate the newborn (lethargy, hepatomegaly, seizures); initiate emergency treatment as indicated by metabolic specialist.
  • Initiate timely confirmatory/diagnostic testing as recommended by specialist.
  • Educate family about signs, symptoms and need for urgent treatment of hypoglycemia (lethargy, seizures).
  • Report findings to newborn screening program.

Diagnostic Evaluation:

Plasma acylcarnitine showing elevated free carnitine C0 with low or normal long-chain acylcarnitines. CPT1 enzyme assays and CPT1A gene sequencing establish the diagnosis.

Clinical Considerations:

CPT1 can have a variable presentation. Critical hypoketotic hypoglycemia is a common presenting feature. Newborns may appear asymptomatic but can progress to fasting hypoketotic hypoglycemia, lethargy, hepatomegaly, and seizures, usually precipitated by fasting or acute illness.

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