Medium
Chain Acyl-CoA Dehydrogenase Deficiency (MCAD)
Medium chain acyl-CoA dehydrogenase
(MCAD) deficiency is the most common defect in mitochondrial
b-oxidation in humans. It is estimated that in the Caucasian
population 1 in 50 individuals is a carrier and 1 in 10,000 live
births will be affected. The disease shows an autosomal recessive
pattern of inheritance and is characterized by a wide spectrum
of clinical features including developmental delay, behavioral
problems, fasting intolerance, and vomiting. Patients demonstrate
hypoglycemia and medium chain dicarboxylic aciduria. If untreated
the disease can lead to coma and premature death.
Molecular analysis of MCAD gene has
shown that one mutation, K304E, accounts for approximately 90%
of the total mutant alleles among Caucasian individuals. The
polymerase chain reaction followed by restriction endonuclease
digestion is utilized to test for the presence of the K304E mutation.
Specimen requirements: 5 to 10 ml of peripheral blood
collected in an EDTA (lavender top) Vacutainer tube is preferred.
The minimal blood needed for reliable DNA isolation is 3 ml.
If necessary, ACD solution A Vacutainer tubes (yellow top)
may be substituted. Prenatal studies require two confluent T-25
flasks containing cultured CVS material or amniocytes. A maternal
blood sample is also requested for prenatal analysis.
Transport: Please
contact the Molecular Diagnostic
Laboratory Coordinator (1-800-473-9411) for shipping information. The specimen
should be kept at room temperature and delivered via overnight
shipping. FedEx delivery is preferred. 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 a Friday can be safely designated for Monday delivery.
Analysis standards: Analysis will be completed within
2 weeks from sample receipt. The quality and interpretation
of test results are assessed by the laboratory director. Technical
staff independently assess the quality and interpretation of
the test. The Greenwood Genetic Center Molecular Diagnostic Laboratory
is CLIA certified and actively participates in CAP proficiency
surveys.
Reporting of Test Results: Test results and their interpretation will be
mailed and/or faxed following completion of the test. Verbal
reports will be telephoned to the person(s) requesting the test
when an abnormal test result occurs. Consultation with the laboratory
director is available and explanations of testing protocols will
be supplied upon request.
CPT Codes: 83890, 83898,
83912
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