Very Long Chain Fatty Acid Deficiency: ACADVL Sequencing

Turnaround Time

2 weeks

CPT Code(s)

81406

Cost

$1,500

Genes

• Very Long Chain Fatty Acid Deficiency (VLCAD)

VLCAD deficiency is an inborn error of fatty acid metabolism caused by the deficiency of very long chain acyl-CoA dehydrogenase. Patients are often identified via newborn screening. Confirmation via molecular testing is then recommended. Three phenotypes of VLCAD deficiency have been described: 1) The severe, early-onset form typically presents in the first months of life with hypotonia, cardiomyopathy, arrhythmias, pericardial effusion, hepatomaegaly and hypoglycemia 2). The early childhood-onset form presents with hepatomegaly and hypoketotic hypoglycemia 3) The later-onset form includes exercise intolerance, muscle pain and/or cramps and intermittent rhabdomyolysis.

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Sanger Sequencing

Sequencing of the gene will detect mutations in 93% of individuals with VLCAD deficiency.

The preferred sample type is 3-5 ml of peripheral blood collected in an EDTA (purple top) tube. Extracted DNA, dried blood spots, and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient.

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.