Preferred initial molecular test to confirm a diagnosis or identify carriers of medium chain acyl-CoA dehydrogenase (MCAD) deficiency for individuals with suggestive clinical and/or biochemical findings. To diagnose or rule out MCAD deficiency, refer to Acylcarnitine Quantitative Profile, Plasma (0040033), Acylglycine, Quantitative, Urine (0081170), and Organic Acids, Urine (0098389).
Polymerase Chain Reaction/Fluorescence Monitoring
DNA isolation: Sun-Sat; Assay: Sun-Sat
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
Negative: The patient is negative for the ACADM 985A>G and 199T>C mutations. Persons affected with MCAD deficiency may have rare mutations in ACADM or other genes not detected by this assay.
Background Information for Medium Chain Acyl-CoA Dehydrogenase (ACADM) 2 Mutations:
Characteristics: Limited mitochondrial fatty acid beta-oxidation leading to hypoglycemia, lethargy, seizures, hypoketotic aciduria, vomiting, hepatomegaly, hepatic failure, encephalopathy, and sudden death. Manifestations often triggered by prolonged fasting or other metabolic stressors.
Incidence: 1 in 15,000.
Inheritance: Autosomal recessive.
Cause: Deleterious ACADM gene mutations.
Clinical Sensitivity: 75 percent for MCAD deficiency.
Mutations Tested: ACADM mutations c.985A>G (p.K329E, also known as K304E) and c.199T>C (p.Y67H, also known as Y42H).
Methodology: Polymerase chain reaction and fluorescence monitoring.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. ACADM mutations other than c.985A>G and c.199T>C will not be detected.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|0051209||MCAD Mutation A985G||50397-9|
|0051217||MCAD Mutation T199C|
|0051242||Medium Chain Acyl-CoA Interpretation||43242-7|
- MCAD Deficienc
- MCAD gene mutation assay