Molecular (DNA) test to confirm a diagnosis of Very Long Chain Dehydrogenase (VLCAD) deficiency when Very Long-Chain Acyl-CoA Dehydrogenase Deficiency (ACADVL) Sequencing (2002001) does not identify two causative mutations. Carrier testing for individuals with a family history of a deletion or duplication in the ACADVL gene.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Fatty acid beta-oxidation disorder leading to hypoketotic hypoglycemia, dicarboxylic aciduria, hepatic failure, Reye-like symptoms, cardiomyopathy, skeletal myopathy, and sudden death. Clinical presentation varies in severity and age of onset.
Incidence: Approximately 1 in 40,000.
Inheritance: Autosomal recessive.
Cause: Deleterious ACADVL gene mutations.
Clinical Sensitivity: Unknown; may be as high as 10 percent.
Methodology: Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large ACADVL coding region deletions/duplications.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. ACADVL single base pair substitutions, small deletions/duplications, regulatory region mutations and deep intronic mutations will not be detected; deletion/duplication breakpoints will not be determined. Mutations in genes other than ACADVL will not be detected. Deletions/duplications in exon 2 of ACADVL will not be detected.
|Component Test Code*||Component Chart Name||LOINC|
|2004209||VLCAD DD Specimen|
|2004210||VLCAD (ACADVL) Del/Dup Interpretation|
- ACADVL deletion/duplication assay