Sign in →

Test Code PEND KNOWN Pendred Known Mutation

Clinical System Name

Pendred Known Mutation





This test involves targeted analysis for SLC26A4 gene mutations previously identified through clinical testing of a family member or  research testing of the individual.  For full gene sequencing please see Pendred Sequencing.

Sample Requirements

Specimen: Whole blood, cord blood

Container(s): Lavender/EDTA, Yellow/ACD A or B

Preferred Vol: 3 mL

Minimum Vol: 1 mL


Note: Heparin samples (Green tops) are unacceptable.


Specimen: Extracted DNA

Minimum: 10µg

Note: DNA concentration minimum 50 µg/mL; 260/280 ratio 1.70-2.00


Specimen: Cultured cells

Acceptable:  Fibroblasts

Container(s): T-25 flasks

Preferred Vol: 2 flasks

Processing Instructions

Reject due to: Heparin

Spin: No

Aliquot: No

Temp: Refrigerate

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 2-3 weeks


Performing Laboratory

Seattle Children's Laboratory


Department:  Molecular Genetics Laboratory

Phone: 206-987-3872


Lab Client Services: 206-987-2617


Lab Genetic Counselors:

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

81403 (updated 1/20/16 by jconta)

Special Instructions

Please provide copies of proband reports when requesting known mutation analysis for cases NOT performed by Seattle Children's Lab.


Links to:  Pendred Syndrome/DFNB4 - GeneReview


Molecular Genetics

Clinical Utility

Targeted mutation analysis for Pendred syndrome and DFNB4.


Mutations in the SLC26A4 gene cause Pendred syndrome (PDS) and DFNB4. Pendred syndrome is an autosomal recessive syndromic disorder characterized by bilateral sensorineural hearing impairment (typically congenital), vestibular dysfunction, temporal bone abnormalities such as enlargement of the vestibular aqueduct (EVA), and euthyroid goiter. DFNB4 is an autosomal recessive form of nonsyndromic deafness characterized by vestibular dysfunction and EVA without thyroid defects. SLC26A4 mutations may account for 7-13% of all congenital hearing impairment.  SLC26A4 mutations account for approximately half of PDS/DFNB4 cases and are the second most common cause of genetic hearing impairment. Deletion/duplication analysis of SLC26A4 and analysis of the FOXI1 and KCNJ10 genes could be considered for individuals with a clinical history suggestive of Pendred syndrome/DFNB4 and one or no identifiable mutations in the SLC26A4 gene.