ARUP's Laboratory Test Directory

Apolipoprotein B (APOB) Mutation Detection : 0055654
[ image for: Consent Form Recommended]
Consent Form Recommended
[ image for: Additional Technical Information]
Additional Technical Information


Mnemonic: APO B

Ordering Recommendation: Detects suspected familial defective APOB-100 mutations in hypercholesterolemic individuals.
Methodology: Polymerase Chain Reaction/Fluorescence Monitoring
Performed: Mon, Thu
Reported: 2-7 days
Specimen Required: Collect: Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation: Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature: Refrigerated.

Stability (collection to initiation of testing): Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval:
R3500Q Negative: This patient is negative for the R3500Q (G9775A) mutation.
R3500W Negative: This patient is negative for the R3500W (C9774T) mutation.
Interpretive Data: Background information for Apolipoprotein B Mutation Detection:
Characteristics:
Familial defective APOB-100 (FDB) is a disorder which increases an individual's risk for coronary artery disease. FDB is caused by mutations in the APOB gene that prevents the APOB-LDL complex from binding to the LDL receptor.
Incidence:
1.5 percent of familial hypercholesterolemia is due to an APOB gene mutation. 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 percent of FDB patients).
Inheritance:
Autosomal dominant
Penetrance:
Heterozygous carriers of an APOB mutation have an increased risk for coronary artery disease, although with a reduced penetrance. 40 percent of males and 20 percent of females heterozygous for these mutations develop coronary artery disease. Homozygotes or compound heterozygotes for R3500Q/R3500W are at greater risk for disease.
Cause:
Ligand-defective apolipoprotein B-100.
Methodology:
Patient DNA is assayed for Arg3500Gln and Arg3500Trp mutations in the APOB gene by polymerase chain reaction (PCR) and fluorescence monitoring using hybridization probes.
Analytical Sensitivity & Specificity:
Sensitivity and specificity for detection of this mutation are 99.9 percent.
Limitations:
Mutations in other genes or other mutations in the APOB gene that may cause familial hypercholesterolemia or increased risk for coronary artery disease are not ruled out.

This test is not recommended for nonsymptomatic patients under 18 years of age.

This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
CPT Code(s): 81401