Alport Syndrome, X-linked (COL4A5) Sequencing and Deletion/Duplication
2002398
Ordering Recommendation
Diagnostic testing for X-linked Alport syndrome.  Carrier screening for X-linked Alport syndrome. Predictive testing for X-linked Alport syndrome.
Mnemonic
ALPORT FGA
Methodology
Polymerase Chain Reaction/ Sequencing/Multiplex Ligation-dependent Probe Amplification
Performed
Varies
Reported
Within 35 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: 2 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 and Deletion/Duplication
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:
Approximately 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:
Pathogenic type 4 collagen alpha chain 5 (COL4A5) mutations.
Clinical Sensitivity:
Greater than 80 percent for X-linked Alport syndrome in males or females.
Methodology:
Bidirectional sequencing of the entire COL4A5 coding region and intron-exon boundaries and multiplex ligation-dependent probe amplification (MLPA) to detect large COL4A5 coding region deletions and duplications.
Analytical Sensitivity & Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations and deep intronic mutations will not be detected. Breakpoints of deletions/duplications will not be determined. Mutations in genes, other than COL4A5, are not evaluated.



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
 
CPT Code(s)
81407; 81408
Components
Component Test Code*Component Chart Name
2002399ALPORT FGA Specimen
2002401Alport (COL4A5) Seq and Del/Dup Interp
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Alport syndrome molecular testing
  • X-linked Alport syndrome molecular testing