ARUP's Laboratory Test Directory

Macular Degeneration, Age-Related, 2 DNA Markers : 0051674
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Additional Technical Information
  


Mnemonic: AMD

Ordering Recommendation: Assess genetic risk for age-related macular degeneration.
Methodology: Polymerase Chain Reaction/Fluorescence Monitoring
Performed: Mon, Thu
Reported: 4-10 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:
By report
Interpretive Data: Background Information for Age-Related Macular Degeneration (AMD):
Characteristics:
AMD is a degenerative disease of the retina that results in progressive loss of central vision; it is the most common cause of irreversible vision loss in the Western world. Dry AMD (90 percent of cases) is characterized by the presence of extracellular deposits called drusen; wet AMD (10 percent of cases) is associated with neovascularization of the choroid.
Prevalence:
1.6 percent at 52-64 years, 11 percent at 65-74 years and 28 percent at >74 years.
Inheritance:
Multifactorial.
Risk Factors:
Cigarette smoking, increasing age, BMI>24, dietary fat intake, Caucasian ethnicity, female gender and genetic mutations (below).
Mutations Tested:
A69S (c.205G>T) in the ARMS2 gene (also known as LOC387715) (Age-related maculopathy susceptibility 2) and Y402H (c.1277T>C) in the CFH gene, encoding complement factor H. These mutations are associated with approximately 70 percent of the risk of AMD.
Clinical Sensitivity & Specificity:
Unknown.
Methods:
Polymerase chain reaction and fluorescence monitoring.
Analytical Sensitivity & Specificity:
99 percent.
Limitations:
Mutations other than those targeted will not be detected. Rare diagnostic errors may occur due to primer or probe site mutations. The mutations tested are associated with risk of AMD; they may not be causal for the disorder.

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
Note: This test is not recommended for nonsymptomatic patients under 18 years of age. This assay detects the following variants: Y402H in CFH (complement factor H), and rs10490924 to assess age-related macular degeneration risk.
CPT Code(s): 81401