Preferred molecular (DNA) test to confirm a diagnosis of primary carnitine deficiency following clinical and/or biochemical presentation. To diagnose or rule out primary carnitine deficiency, refer to Carnitine, Free & Total (Includes Carnitine, Esterified) (0080068) and Carnitine, Free and Total, Urine (0081308).
Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 2 mL)
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Background information for Primary Carnitine Deficiency (SLC22A5) Sequencing and Deletion/Duplication:
Characteristics: Hypoketotic hypoglycemia during periods of fasting, hepatomegaly, Reye syndrome, sudden infant death, developmental delay, cardiac and/or skeletal myopathy, hypotonia and enlarged heart.
Incidence: 1 in 40,000 for European Caucasian and Japanese, lower in other populations.
Inheritance: Autosomal recessive.
Cause: Pathogenic SLC22A5 gene mutations.
Clinical Sensitivity: May be as high as 95 percent.
Methodology: Bidirectional sequencing of the entire coding region and intron-exon boundaries of SLC22A5 gene; Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large SLC22A5 coding region deletions/duplications.
Analytical Sensitivity: Greater than 99 percent.
Limitations: Mutations in genes other than SLC22A5 will not be detected; deletion/duplication breakpoints will not be determined; deep intronic mutations and promoter mutations in the SLC22A5 gene will not be detected. Mutations within the primer/probe regions could affect the analytical sensitivity of this assay. Diagnostic errors can occur due to rare sequence variations.
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|2004204||PCD FGA Specimen|
|2004205||Primary Carnitine Deficiency Interpretat|
- Carnitine Deficiency
- SLC22A5 sequencing and deletion/duplication assay