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).
Polymerase Chain Reaction/Sequencing
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
Transport 3 mL whole blood. (Min: 1 mL)
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Background information for Primary Carnitine Deficiency (SLC22A5) Sequencing:
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: Deleterious SLC22A5 gene mutations causing a non-functional protein (OCTN2).
Clinical Sensitivity: Approximately 82 percent.
Methodology: Bidirectional sequencing of the entire coding region and intron/exon boundaries of SLC22A5 gene.
Analytical Sensitivity: Greater than 99 percent.
Limitations: Mutations in genes other than SLC22A5 will not be detected; large deletions, deep intronic mutations and promoter mutations in the SLC22A5 gene are not detected by this assay; analytical sensitivity may be compromised by rare primer site mutations. Diagnostic errors can occur due to rare sequence variations.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|0051681||PCD Sequencing Interpretation|
|2001371||PCD FGS Specimen|
- OCTN2 Sequencing
- SLC22A5 sequencing