Usher Syndrome, Types 1F and 3 (PCDH15 and CLRN1), 2 Variants
Ordering Recommendation

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

Polymerase Chain Reaction/Fluorescence Monitoring
Tue, Fri
5-10 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Unacceptable Conditions
Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes. 
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:
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.

Hotline History
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
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