Ordering Recommendation

Carrier screening or diagnostic testing for Usher syndrome types 1F and 3 for individuals of Ashkenazi Jewish descent.

Mnemonic
USHER
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Tue, Fri

Reported

5-10 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month

Reference Interval

By report

Interpretive Data

Background Information for Usher Syndrome, Types 1F and 3 (PCDH15 and CLRN1), 2 Variants:
Characteristics:
Usher syndrome type 1F is characterized by congenital, bilateral, profound sensorineural hearing loss, adolescent-onset retinitis pigmentosa and loss of vestibular function. Usher syndrome type 3 is characterized by post-lingual, progressive hearing loss, late-onset progressive vision loss due to retinitis pigmentosa and variable loss of vestibular function.
Incidence: In Ashkenazi Jewish individuals - 1 in 20,500 for Usher syndrome type 1F; 1 in 82,000 for Usher syndrome type 3.
Inheritance: Autosomal recessive.
Cause: PCDH15 and CLRN1 pathogenic variants.
Variants Tested: PCDH15 p.R245X (c.733C>T), CLRN1 p.N48K (c.144T>G).
Clinical Sensitivity: In Ashkenazi Jewish individuals - 62 percent for Usher syndrome, type 1F; 98 percent for Usher syndrome, type 3. Sensitivities unknown in other ethnicities.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Variants other than those tested will not be detected. Diagnostic errors can occur due to rare sequence variations.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
CPT Codes

81400

Components
Component Test Code* Component Chart Name LOINC
2013751 Usher Syndrome Types 1F and 3, Specimen
2013752 Usher Syndrome Types 1F and 3, Allele 1
2013753 Usher Syndrome Types 1F and 3, Allele 2
2013754 Usher Syndrome Types 1F and 3, Interp
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
Usher Syndrome, Types 1F and 3 (PCDH15 and CLRN1), 2 Variants