MEDIUM CHAIN ACYL-CoA DEHYDROGENASE DEFICIENCY (MCAD)

ACADM Sequencing

MITOCHONDRIAL DNA ANALYSIS

The medium chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common enzyme deficiency in fatty acid oxidation. Patients with MCAD deficiency may present clinically as an acute encephalopathy. Apparent life threatening events (ALTEs) have also been reported. During symptomatic episodes, patients may have hypoketotic hypoglycemia. Symptoms are commonly precipitated by metabolic stress such as fasting or infection. An A to G transversion at nucleotide 985 of the cDNA coding region causing the change of amino acid lysine at position 304 to glutamate is the most common mutation in MCAD deficiency accounting for more than 80% of the mutant alleles. Target Analysis for the common mutation (K304E) and sequencing analysis of the entire coding region of the medium-chain acyl-CoA dehydrogenase (ACADM) gene is available on a clinical basis at the Medical Genetics Laboratories at Baylor College of Medicine.

Reasons for Referral:

To confirm the diagnosis of MCAD deficiency.
Carrier testing

Testing Methodology:

Full Sequencing: PCR amplification of all exons contained in the MCAD gene coding region will be performed on patients genomic DNA. Direct sequencing of the amplification products is performed in both the forward and reverse directions using automated fluorescence dideoxy sequencing methods.

Common Mutation Analysis: Our laboratory uses DNA amplification (PCR) and an automated mini-sequencing methodology to test for the K304E mutation in the MCAD gene.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 14 cc; Child: 6 cc; Infant: 2-3 cc

Turnaround Time:

Full Sequencing: 4 weeks
Common Mutation Analysis: 2 weeks
Known Familial Mutation: 2 weeks

CPT Codes and Prices:

Full Sequencing: 83904x24, 83898x12, 83912, 83891
One Mutation Analysis: 83904x4, 83898x2, 83912, 83891, 83894x2
Known familial mutation: 83904x4, 83898x2, 83912, 83891, 83894x2

Shipping Information

Forms:

>> Gene Sequencing Requisition

Test Codes:

Full Sequencing: 3115
One Mutation Analysis: 3117
Known Familial Mutation: 3116