Get More Help in NevadaCarnitine Palmitoyltransferase 1A (CPT 1) Deficiency
Guidance for primary care clinicians receiving a positive newborn screen result
Description
Carnitine palmitoyltransferase 1A (CPT1) is a mitochondrial enzyme involved in the conjugation of fatty acids to carnitine for subsequent transfer inside mitochondria through the action of a translocase. Variants in the CPT1A gene cause CPT1 deficiency. Deficient CPT1 activity results in impaired energy production, which usually manifests during prolonged fasting and/or increased energy demands (fever, stress), resulting in acute hepatic encephalopathy and hypoketotic hypoglycemic crises. CPT1A is predominantly expressed in the liver; therefore, unlike other fatty acid oxidation disorders, the muscle and heart are not primarily affected. Acute fatty liver of pregnancy may occur in a heterozygous mother of an affected fetus. Presentation in the neonatal period is rare.
Clinical Characteristics
- Poor appetite
- Vomiting
- Lethargy
- Lab findings:
- Hyperammonemia
- Elevated transaminases
- Metabolic acidosis
- Hypoglycemia
Incidence
Primary Care Management
Next Steps After a Positive Screen
- Contact the family to inform them of the positive result and ask if the infant has shown signs of lethargy, poor feeding, or seizures.
- Consult with a pediatric metabolic specialist immediately.
- Evaluate the newborn for lethargy, liver disease, or seizures. If any of these signs are present or the newborn is ill, transport to a hospital for further treatment with help from the metabolic specialist.
- Initiate confirmatory/diagnostic testing and management, as recommended by the specialist (see below).
Confirming the Diagnosis
- To confirm the diagnosis of CPT1, work with Newborn Screening Services (see NV providers [2]).
- Additional testing may include glucose, blood gas, electrolytes, liver function tests, ammonia level, quantitative plasma acylcarnitine profile, enzyme activity assay in cultured fibroblasts, and CPT1A gene sequencing. The increased C0/(C16+C18) ratio is better detected from the dried blood spot collected for newborn screening. In plasma, C0 can be only mildly increased with low levels of C16 and C18.
If the Diagnosis is Confirmed
- For evaluation and ongoing collaborative management, consult Biochemical Genetics (Metabolics) (see NV providers [2]).
- Educate the family regarding signs, symptoms, and the need to avoid fasting and seek urgent care when the infant becomes ill. See CPT1 Deficiency - Information for Parents (STAR-G) for additional information.
- Provide a letter and, when old enough, a MedicAlert bracelet indicating the risk for hypoglycemia and need for urgent treatment with IV glucose when illness or stress leads to symptoms.
- Provide frequent, low-fat, and high-carbohydrate meals and snacks. In some cases, cornstarch is added to meals.
- Medium-chain triglyceride oil supplements may be indicated for some children.
Resources
Information & Support
Related Portal Content
Fatty Acid Oxidation Disorders (FAQ)
Answers to frequently asked questions about a diagnosis of a
fatty acid oxidation disorder.
After a Diagnosis or Problem is Identified
Families can face a big change when their baby tests positive
for a newborn condition. Find information about A New Diagnosis - You Are
Not Alone; Caring for Children with Special Health Care Needs; Assistance in
Choosing Providers; Partnering with Healthcare Providers; Top Ten Things to
Do After a Diagnosis.
Affording Formula
Tips for finding discounted formula and supplementation.
For Professionals
CPT1 Deficiency (GeneReviews)
Detailed information addressing clinical characteristics, diagnosis/testing, management, genetic counseling, and molecular
pathogenesis; from the University of Washington and the National Library of Medicine.
For Parents and Patients
CPT1 Deficiency - Information for Parents (STAR-G)
A fact sheet, written by a genetic counselor and reviewed by metabolic and genetic specialists, for families who have received
an initial diagnosis of this newborn disorder; Screening, Technology and Research in Genetics.
Fatty Oxidation Disorders (FOD) Family Support Group
Information for families about fatty acid oxidation disorders, support groups, coping, finances, and links to other sites.
Tools
ACT Sheet for Carnitine Palmitoyltransferase I (CPT I) Deficiency (ACMG)
Provides recommendations for clinical and laboratory follow-up of the newborn with out-of-range screening results, along with
national resources for clinicians and families; American College of Medical Genetics.
NV ACT Sheet for CPT I (CO/C16+C18) (ACMG) (
123 KB)
Provides recommendations for clinical and laboratory follow-up of the newborn with out-of-range screening results, along with
national and local resources for clinicians and families; American College of Medical Genetics.
Algorithm for Carnitine Palmitoyltransferase 1A (CPT 1) Deficiency [Elevated C0/C16+C18] (ACMG)
An algorithm of the basic steps involved in determining the final diagnosis of an infant with a positive newborn screen; American
College of Medical Genetics.
Services for Patients & Families in Nevada (NV)
| Service Categories | # of providers* in: | NV | NW | Other states (3) (show) | | NM | RI | UT |
|---|---|---|---|---|---|---|---|---|
| Biochemical Genetics (Metabolics) | 2 | 1 | 1 | 3 | 2 | |||
| Early Intervention for Children with Disabilities/Delays | 30 | 3 | 34 | 13 | 51 | |||
| Medical Genetics | 5 | 1 | 2 | 4 | 7 | |||
| Newborn Screening Services | 2 | 1 | 3 | 2 | 3 | |||
For services not listed above, browse our Services categories or search our database.
* number of provider listings may vary by how states categorize services, whether providers are listed by organization or individual, how services are organized in the state, and other factors; Nationwide (NW) providers are generally limited to web-based services, provider locator services, and organizations that serve children from across the nation.
Helpful Articles
PubMed search for CPT1 deficiency, last 15 years.
Longo N, Amat di San Filippo C, Pasquali M.
Disorders of carnitine transport and the carnitine cycle.
Am J Med Genet C Semin Med Genet.
2006;142C(2):77-85.
PubMed abstract / Full Text
Page Bibliography
Bennet MJ, Santanii AB.
Carnitine Palmitoyltransferase 1A Deficiency.
GeneReviews; (2016)
https://www.ncbi.nlm.nih.gov/books/NBK1527/. Accessed on Oct 28, 2022.
Longo N, Amat di San Filippo C, Pasquali M.
Disorders of carnitine transport and the carnitine cycle.
Am J Med Genet C Semin Med Genet.
2006;142C(2):77-85.
PubMed abstract / Full Text
Schulze A, Lindner M, Kohlmuller D, Olgemoller K, Mayatepek E, Hoffmann GF.
Expanded newborn screening for inborn errors of metabolism by electrospray ionization-tandem mass spectrometry: results, outcome,
and implications.
Pediatrics.
2003;111(6 Pt 1):1399-406.
PubMed abstract