ARUP's Laboratory Test Directory
| 0055654: Apolipoprotein B Mutation Detection |
![[ image for: Consent Form Recommended]](icon_4.jpg){kind=icon} | Consent Form Recommended |
| Test Mnemonic: APO B | |
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Methodology: 3Polymerase Chain Reaction/Fluorescence Monitoring
Performed: Mon, Thu Reported: 2-7 days |
| Specimen Required: | |
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Collect: One 5 mL lavender (EDTA) or pink (K2EDTA). Also acceptable: green (sodium or lithium heparin), lt. blue (sodium citrate), or yellow (ACD Solution A).
Transport: 5 mL whole blood at 2-8°C. (Min: 1 mL) Unacceptable Conditions: Frozen or severely hemolyzed specimens. Serum. Stability: Ambient: 3 days; Refrigerated: 1 week; Frozen: Unacceptable |
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| Reference Interval: |
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R3500Q Negative: This patient is negative for the R3500Q (G9775A) mutation. R3500W Negative: This patient is negative for the R3500W (C9774T) mutation. |
| Interpretive Data: | |
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Familial defective apo B-100 (FDB) is an autosomal dominant disorder caused by mutations in the apo B gene that prevents the apo B-LDL complex from binding to the LDL receptor. 15% of familial hypercholesterolemia is due to this ligand-defective apolipoprotein B-100. The most common mutation, Arg3500Gln, has a frequency of 1/500-1/700 in Caucasian populations of North America and Europe. The rare Arg3500Trp mutation originally described in the Scottish population also has been identified in FDB of Asian descent (approximately 2% of FDB patients). Heterozygous carriers of an apo B mutation have an increased risk for coronary artery disease, although with a reduced penetrance. 40% of males and 20% of females heterozygous for these mutations develop coronary artery disease. Homozygotes or compound heterozygotes for R3500Q/R3500W are at greater risk for disease. Mutations in other genes or other mutations in the apo B gene that may cause familial hypercholesterolemia or increased risk for coronary artery disease are not ruled out. Patient DNA is assayed for Arg3500Gln and Arg3500Trp mutations in the apo B gene by polymerase chain reaction (PCR) and fluorescence monitoring using hybridization probes. Sensitivity and specificity for detection of this mutation are 99.9%. This test is not recommended for nonsymptomatic patients under 18 years of age. Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com. Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory. |
| Note: | |
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For a complete description of the Reference Interval, please refer to ARUP's Guide to Clinical Laboratory Testing, which can be found on our Web site at www.aruplab.com. |
| CPT Code(s): | |
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83890 Isolation; 83898 Amplification; 83896 x2 Nucleic acid probes; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders. |