Sample Confirmation Testing: A Short Tandem Repeat-Based Quality Assurance and Quality Control Procedure for the eyeGENE Biorepository.

Quality assurance and quality control (QA/QC) procedures are vital to good biorepository management. The National Eye Institute (NEI) core CLIA-certified laboratory of the eyeGENE(®) Network receives blood from individuals with inherited eye conditions and isolates DNA for clinical genetic diagnostic testing and research. Clinical genetic test results are returned to the affected individuals, making it imperative that sample integrity is preserved throughout laboratory processing. A clinically validated, short tandem repeat (STR)-based approach, termed Sample Confirmation Testing (SCT), was developed to ensure that no significant laboratory errors occurred during processing. SCT uses modified protocols from commercial kits to create and compare STR profiles for each participant's original blood and derived DNA. This QA/QC procedure has been performed on 47% of the more than 6000 participants in the eyeGENE Biorepository and has identified significant laboratory errors in 0.4% of samples tested. SCT improves the quality of the data returned to affected individuals and the data distributed to researchers using eyeGENE samples by ensuring the integrity of the samples and aiding in curation of the biorepository. This approach serves as a model for other repositories to improve sample quality and management procedures.

Prevalence of mutations in eyeGENE probands with a diagnosis of autosomal dominant retinitis pigmentosa.

PURPOSE: To screen samples from patients with presumed autosomal dominant retinitis pigmentosa (adRP) for mutations in 12 disease genes as a contribution to the research and treatment goals of the National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE). METHODS: DNA samples were obtained from eyeGENE. A total of 170 probands with an intake diagnosis of adRP were tested through enrollment in eyeGENE. The 10 most common genes causing adRP (IMPDH1, KLHL7, NR2E3, PRPF3/RP18, PRPF31/RP11, PRPF8/RP13, PRPH2/RDS, RHO, RP1, and TOPORS) were chosen for PCR-based dideoxy sequencing, along with the two X-linked RP genes, RPGR and RP2. RHO, PRPH2, PRPF31, RPGR, and RP2 were completely sequenced, while only mutation hotspots in the other genes were analyzed. RESULTS: Disease-causing mutations were identified in 52% of the probands. The frequencies of disease-causing mutations in the 12 genes were consistent with previous studies. CONCLUSIONS: The Laboratory for Molecular Diagnosis of Inherited Eye Disease at the University of Texas in Houston has thus far received DNA samples from 170 families with a diagnosis of adRP from the eyeGENE Network. Disease-causing mutations in autosomal genes were identified in 48% (81/170) of these families while mutations in X-linked genes accounted for an additional 4% (7/170). Of the 55 distinct mutations detected, 19 (33%) have not been previously reported. All diagnostic results were returned by eyeGENE to participating patients via their referring clinician. These genotyped samples along with their corresponding phenotypic information are also available to researchers who may request access to them for further study of these ophthalmic disorders. (ClinicalTrials.gov number, NCT00378742.).