ARPKD Known PKHD1 Variant Testing (KT2)
Information for Ordering
Acceptable Specimen Types
- Fresh blood sample: 3–6 mL EDTA; no time limitations associated with receipt
- Saliva: OGD-575 DNA Genotek collection kit; kits are provided upon request
- DNA extracted from lymphocyte cells: minimum volume of 25 µL containing 3 µg of DNA; A260/A280 ratio ≥1.8; must be extracted in a CLIA-certified or equivalent laboratory
Turnaround Time
- Blood, saliva, or DNA: Average of 15 working days
Price, CPT Codes, and Z Code
- Sequencing of one exon: $250 USD institutional/self-pay price; CPT code 81403
- Sequencing of two exons: $340 USD institutional/self-pay price; CPT code 81403 × 2
- MLPA: $250 USD institutional/self-pay price; CPT code 81407
- Z code: ZB67K
Candidates for Testing
Testing is offered to established patients and families with previously identified pathogenic variants in PKHD1.
Specimen Shipping and Handling
Please refer to the specimen requirements listed above.
Blood, saliva, and extracted DNA specimens should be shipped at room temperature. Do not ship specimens on ice.
Specimens must be packaged to prevent breakage. Absorbent material must be included to contain liquids if breakage occurs. Specimens must also be shipped in double watertight containers, such as a specimen pouch placed inside the shipping company’s diagnostic envelope.
To request a collection kit, please complete the Collection Kit Request Form.
Before shipping a specimen, please contact the UAB Medical Genomics Laboratory by email at medgenomics@uabmc.edu or by phone at 205-934-5562. Please provide the specimen type, shipment date, and package tracking number so the laboratory can help ensure proper and timely receipt.
Required Forms
About
Disorder Background
Autosomal recessive polycystic kidney disease is characterized by enlarged cystic kidneys and hepatic fibrosis. The diagnosis is often made prenatally or during the neonatal period, although some patients are diagnosed later in life. Disease severity varies widely, and mortality is high during the first months of life in the most severely affected patients.
ARPKD is one of the more common hereditary childhood nephropathies, with an estimated incidence of approximately 1 in 20,000–40,000 individuals. The estimated carrier frequency in the general population is approximately 1 in 70 to 1 in 100.
The PKHD1 gene, also known as Polycystic Kidney and Hepatic Disease 1, is located on chromosome 6p21-p12 and spans approximately 470 kb of genomic DNA. It is the only gene known to be associated with the broad clinical spectrum of autosomal recessive polycystic kidney disease.
More than 80 exons and multiple alternative transcripts have been identified. Pathogenic variants include missense, nonsense, frameshift, splice-site, and multi-exon deletion variants. Variants are distributed throughout the gene, and most affected families carry private familial variants.
Test Description
The ARPKD Known PKHD1 Variant Test provides targeted detection of a previously characterized familial pathogenic variant.
DNA is extracted from the submitted specimen, and the target region is amplified and analyzed by direct Sanger sequencing. MLPA may be performed when targeted analysis of a known deletion or duplication is required.
To offer this testing service, the proband’s pathogenic variant must have been identified previously by the UAB Medical Genomics Laboratory.
View references for this testing.
Other Related Test Options
- ARPKD Prenatal Known PKHD1 Variant Testing (PT2)
- ARPKD Known PKHD1 Variant Linkage Analysis for Informativity (PKDL) and Prenatal Linkage Analysis (PKDPL)
For more information, test requisition forms, or collection kits, please contact the UAB Medical Genomics Laboratory at 205-934-5562 or medgenomics@uabmc.edu.