Diagnostic Test Directory

Molecular Genetics Laboratory

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Laboratory Update

Testing for the Noonan spectrum of disorders is now available at the Molecular Genetics Laboratory. Learn more about Noonan spectrum testing »

Pendred Syndrome (SLC26A4)


    Collect whole blood in a purple top (EDTA) tube.

    Volume Required


    Minimum Required



    Refrigerate sample until shipment. Send the sample at room temperature with overnight delivery for receipt Monday through Friday within 24 hours of collection.


    Whole blood can be refrigerated until shipment.

    Specimen Handling

    Do not heat, freeze or centrifuge blood before shipment. Refrigerate sample until shipment.

Days Performed

Mon - Fri 9:00am to 4:00pm


Seq & Del/dup-4 weeks; Seq-4 weeks; Del/dup-3 weeks; KM-2 weeks


Seq & Del/Dup- 81406, 81479; Sequence Only- 81406; Del/Dup Only- 81479; Known Point Mutation- 81403

Disease Information

Clinical Features:

Pendred syndrome (PS) is an autosomal recessive disorder characterized by sensorineural hearing loss, enlarged vestibular aqueduct (EVA), abnormalities of the cochlea, vestibular dysfunction, temporal bone abnormalities, and goiter development in late childhood to early adulthood. PS is the most common form of syndromic deafness and accounts for roughly 7% of all deafness cases. Both PS and DFNB4 (sensorineural hearing loss without goiter) are due to mutations in the SLC26A4 gene on chromosome 7q.

Test Methods:

We offer DNA sequence analysis and deletion/duplication testing of the entire coding region of the SLC26A4 gene. These tests can be ordered as a panel or individually. PCR amplification and sequence analysis is performed on the coding exon including splice junctions. The patient’s gene sequence is compared to a reference sequence. Sequence variants are classified as mutations, variants of unknown significance or benign variants unrelated to disease. Variants of unknown significance may warrant further studies in the patient and other family members. Mutations in promoters, deep intronic regions and other regulatory regions will not be identified with this assay. Large deletions and duplications will be detected using multiplex ligation-dependent probe amplification assay (MLPA).


The clinical utility of the assay is to support a clinical diagnosis of the disease, facilitate genetic counseling, and assess the risk to other first degree relatives and to facilitate testing of at - risk family members.

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