Ordering Recommendation

Preferred molecular test to diagnose or rule out very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency following clinical and/or biochemical presentation. Also refer to Acylcarnitine Quantitative Profile, Plasma (0040033), Carnitine Panel (0081110), and Organic Acids, Urine (0098389).

Mnemonic
VLCAD FGA
Methodology

Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

28-35 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval
Interpretive Data

Background Information for Very Long-Chain Acyl-CoA Dehydrogenase Deficiency/VLCAD (ACADVL) Deletion/Duplication:
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
: Pathogenic ACADVL gene mutations.
Clinical Sensitivity:
May be as high as 95 percent.
Methodology
: Bidirectional sequencing of the entire coding region and intron-exon boundaries of the ACADVL gene. 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. Regulatory region mutations and deep intronic mutations will not be detected; deletion/duplication breakpoints will not be determined. Deletions/duplications in exon 2 of ACADVL will not be detected.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81406; 81479

Components
Component Test Code* Component Chart Name LOINC
2004213 VLCAD FGA Specimen
2004214 VLCAD (ACADVL) Interpretation
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Aliases
  • ACADVL sequencing and deletion/duplication assay
  • VLCAD
Very Long-Chain Acyl-CoA Dehydrogenase Deficiency (ACADVL) Sequencing and Deletion/Duplication