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Usher Syndrome, Types 1F and 3 (PCDH15 and CLRN1), 2 Variants
2013750
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.
Submit With Order
ARUP Consult®
Disease Topics
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: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Components
Component Test Code*Component Chart NameLOINC
2013751Usher Syndrome Types 1F and 3, Specimen
2013752Usher Syndrome Types 1F and 3, Allele 1
2013753Usher Syndrome Types 1F and 3, Allele 2
2013754Usher 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