STRC-Related Disorders: STRC Sequencing

Test Information

STRC sequencing is a molecular test used to identify variants in the gene associated with STRC-related disorders including type 16 autosomal recessive deafness.

Turnaround Time

3 weeks

CPT Code(s)

81479

Cost

1,000

Genes

  • STRC

Clinical Information

Pathogenic variants in STRC are associated with type 16 autosomal recessive deafness (DFNB16), a nonsyndromic hearing loss, with prelingual onset. DFNB16 is caused by homozygous or compound heterozygous mutations, multi-exon or complete STRC deletions, or gene conversion between the STRC gene and the STRC pseudogene (STRCP1).

Indications

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Methodology

Sanger Sequencing

Detection

Alterations in the stereocilin (STRC) gene are the most common genetic etiology in patients with mild to moderate hearing loss, accounting for roughly 30% of patients in this group, and 16% among all patients with hearing loss. Most variants were large copy number variants (CNVs).

Specimen Requirements

The preferred sample type is peripheral blood collected in an EDTA (purple top) tube - at least 2-3ml for pediatric patients and 5-6ml for adult patients. Extracted DNA and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal Testing Information

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC

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