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Test Code WAS Known WAS Known Mutation

Important Note

Test availability is limited to Seattle Children’s Hospital and University of Washington patients.

Clinical System Name

WAS Known Mutation




This test involves targeted analysis for mutations previously identified through clinical testing of a family member or  research testing of the individual.  It can be used for carrier testing at-risk relatives and prenatal testing for confirmed carriers. Mutations must be known. For full gene sequencing please see WAS Gene Sequencing.


Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by thrombocytopenia with small platelets, eczema, cellular and humoral immunodeficiency, autoimmune disease, and malignancy. WAS is caused by mutations in the Wiskott-Aldrich Syndrome Protein (WASP). WASP is an intracellular protein expressed exclusively in hematopoietic cells. It functions to enhance actin polymerization and branching allowing cells to rearrange their actin cytoskeleton. Cytoskeletal rearrangement is vital for a number of key functions in immune cells such as endocytosis, exocytosis, chemotaxis, and formation of the immunologic synapse.

Sample Requirements

Specimen: Whole blood

Container(s): Dark Green/Sodium Heparin, Lavender/EDTA

Preferred Vol: 5 mL

Minimum Vol: 3 mL


Specimen: Extracted DNA

Minimum: 5µg

Note: DNA concentration minimum 100 µg/mL; 260/280 ratio 1.70-2.00


Specimen: Cultured cells

Acceptable:  Fibroblasts, amniocytes, chorionic villus sampling (CVS)

Container(s): T-25 flasks

Preferred Vol: 2 flasks


Note: Direct testing on amniocentesis and chorionic villus sampling (CVS) is not performed; samples must be cultured by external lab.

Processing Instructions

Reject due to: Clotting

Spin: No

Aliquot: No

Temp: Room temperature

Storage location: Molecular Genetics box in CPA refrigerator #2


Off-site collection: Refrigerate blood samples until ready to ship. Transport all sample types at room temperature via overnight shipping.



Specimen Type Temperature Time
Cultured cells Room temp 3 days
Whole blood, extracted DNA Room temp 3-5 days
Whole blood, extracted DNA Refrigerated 7 days
Extracted DNA Frozen ok


Note: Whole blood samples > 7days may be submitted to be assessed by our lab for acceptability for testing.


STAT Performed TAT
Contact lab Monday - Friday 6-8 weeks


Performing Laboratory

Seattle Children's Laboratory


Department:  Molecular Genetics Laboratory


Lab Client Services: 206-987-2617,

Lab Genetic Counselor:

Reference Range

Interpretive report will be provided


Method: PCR + Sequencing


Limitations: This test is for targeted known mutation analysis only.  Mutations must be known

CPT Codes


Special Instructions

Links to:  Immunology Diagnostic Laboratory


IDL Requisition

Clinical Utility

Determine if there is occurrence of variation in patient WASP sequence by targeted analysis for mutations previously identified through clinical testing of a family member or  research testing of the individual.