Alport Syndrome, X-linked (COL4A5) Sequencing
0051786
Ordering Recommendation
Acceptable first-line genetic test for the detection of mutations causing X-linked Alport syndrome.
Mnemonic
ALPORT FGS
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
Within 28 days  
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
  
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.  
Unacceptable Conditions
  
Remarks
  
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
   
Interpretive Data
Background Information for Alport Syndrome, X-linked (COL4A5) Sequencing:
Characteristics:
Progressive renal and cochlear disease with 30-40 percent incidence of ocular involvement; 60 percent of males reach end stage renal disease by age 30 and 85 percent have sensorineural deafness by age 40.
Incidence:
Estimated to be between 1 in 5,000 to 1 in 50,000 live births.
Inheritance:
X-linked recessive; de novo mutations in 10-15 percent of affected males.
Penetrance:
Variable depending on mutation and sex..
Cause:
Type 4 collagen (COL4A5) alpha chain mutations.
Clinical Sensitivity:
Greater than 80 percent for X-linked Alport syndrome.
Methodology:
Bidirectional sequencing of the entire COL4A5 coding region and intron-exon boundaries.
Analytical Sensitivity & Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Regulatory region and deep intronic mutations will not be detected. Large deletions/duplications will not be detected in females. Mutations in genes other than COL4A5 are not evaluated.





See Compliance Statement C: www.aruplab.com/CS
Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
 
Note
 
CPT Code(s)
81408
Components
Component Test Code*Component Chart NameLOINC
0051787Alport Syndrome (COL4A5) Sequencing 
2001337ALPORT FGS Specimen 
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Aliases
  • Alport syndromesequencing assay
  • X-linked Alport syndrome molecular testing