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Polycystic Kidney Disease, Autosomal Dominant (PKD1 and PKD2) Sequencing and Deletion/Duplication
2012250
Ordering Recommendation

Preferred test for molecular confirmation of a suspected clinical diagnosis of autosomal dominant polycystic kidney disease (ADPKD).

Mnemonic
ADPKD FGA
Methodology
Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification
Performed
Sun-Sat
Reported
35-42 days
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
ARUP Consult®
Disease Topics
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 Polycystic Kidney Disease, Autosomal Dominant (PKD1 and PKD2) Sequencing and Deletion/Duplication

Characteristics:
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is typically an adult-onset, multisystem disorder. Renal findings include: bilateral renal cysts, renal insufficiency, renal pain, hypertension, dilated renal tubules, enlarged kidneys, and end-stage renal disease (ESRD). Extra-renal findings include cysts in other organs, including liver, pancreas, seminal vesicles, and arachnoid membrane. Connective tissue findings include intracranial aneurysms, dolichoectasia, dilation of the aortic root, aortic dissections, mitral valve prolapse, and abdominal wall hernias. Fifty percent of individuals with ADPKD will develop ESRD by age 60.
Prevalence: 1:500-1:1,000 in the U.S.
Inheritance: Autosomal dominant; 5-10 percent of cases are de novo.
Penetrance: Age-dependent; nearly all older adults develop multiple renal cysts. The average age of onset for ESRD in individuals with PKD1 and PKD2 mutations is 54 and 74 years, respectively.
Cause: Pathogenic PKD1 or PKD2 gene mutations. In cases with an identifiable molecular cause, 85 percent are attributed to PKD1 and 15 percent are attributed to PKD2.
Clinical Sensitivity: 90 percent for ADPKD. Approximately 87 percent of cases are due to sequence variants and up to 3 percent of cases result from large deletions/duplications in PKD1 or PKD2.
Methodology: Bidirectional sequencing of the entire coding region and intron/exon boundaries of the PKD1 and PKD2 genes. A large region of PKD1, including exons 1-33, is duplicated six times on the same chromosome; therefore, to distinguish the PKD1 gene from the PKD1-like pseudogenes, long range PCR followed by site-specific PCR is used to sequence PKD1 exons 1-33. Multiplex ligation-dependent probe amplification (MLPA) is used to detect large exonic deletions/duplications of PKD1 or PKD2.
Analytical Sensitivity and Specificity: 99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations and deep intronic mutations in PKD1 or PKD2 will not be detected. Large deletions/duplications of PKD1 exons 1, 2, 4, 8, 17, 24, 28, 32, 34, and 45 will not be detected. Mosaic mutations in PKD1 or PKD2 may not be detected. Breakpoints for large deletions/duplications will not be determined. Mutations in genes other than PKD1 and PKD2 are not assessed by this assay.

Note
CPT Code(s)
Components
Component Test Code*Component Chart NameLOINC
2012251ADPKD Seq and Del/Dup Specimen31208-2
2012252ADPKD Seq, Del/Dup Interp35474-6
* 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
  • ADPKD
  • Adult polycystic kidney disease (APKD)
  • Autosomal dominant polycystic kidney disease
  • Polycystic kidney disease type 1
  • Polycystic kidney disease type 2