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Model Proficiency Evaluation Survey for TREC Assay in Newborn Screening for SCID. Francis K. Lee, Ph.D . Senior Service Fellow (Research Microbiologist) Newborn Screening Translation Research Initiative, CDC Emeritus Professor of Pediatrics, Emory University School of Medicine .
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Model Proficiency Evaluation Survey forTREC Assay in Newborn Screening for SCID Francis K. Lee, Ph.D. Senior Service Fellow (Research Microbiologist) Newborn Screening Translation Research Initiative, CDC Emeritus Professor of Pediatrics, Emory University School of Medicine Newborn Screening Molecular Workshop June 28-30, 2011 National Center for Environmental Health · Division of Laboratory Sciences Newborn Screening and Molecular Biology Branch
DBS Specimen Preparation Decisions! Decisions! DNA Extract (from 3 mm punch) DNA on DBS (2mm punch) Quantitative ASSAY Primers & Probes Singleplex Multiplex Real time PCR Endpoint PCR 96 /386 well format Calibrator Plasmids Transfected Cells
Classification of TREC Assay Results for NBS Screen Negative Screen Positive F/U Required (SCID-like) F/U Required (Result cannot be reliably interpreted) Control Gene Below Cutoff Above Cutoff Indeterminate / Unsatisfactory Below Cutoff Above Cutoff ----------------------- TREC Content
Newborn Screening for SCID CDC Reference Materials Model Performance Evaluation Surveys
DBS Reference Materials for the TREC Assay • DBSfor Screen Normal Phenotype (3 types) • TREC above lower limit of expected range (H, M, L) • Control Gene above lower limit of expected range • DBSfor SCID-Like Phenotype • TREC below lower limit of expected range • (Very low or undetectable) • Control Gene above lower limit of expected range • DBSfor Indeterminate/Unsatisfactory Results • TREC below lower limit of expected range • Control Gene below lower limit of expected range
DBS Reference Materials for TREC Assay • DBS made from SerialDilutions of Cord Blood • Cord blood at median of expected range for TREC • Dilute into lymphocyte-depleted blood • (No detectable TREC) • Equal-volume serial dilutions: • 100%, 50%, 25%, 12%, 6%, 3% • Assay development; Calibration; • Assess Comparability of Decision Ranges
No Follow-up Required Follow-up Required
Model Performance Evaluation Surveys (“MPES” = Pilot PT) • Sendouts at 4-6 week interval • Five DBS w/ prior consensus categorization • Additional DBS included for RM evaluation • 11 Laboratories currently participating • >500 results to date
CDC NSTRI – SCID Project Team Robert Vogt ( rfv1@cdc.gov 770-488-7895) Francis Lee ( flee1@cdc.gov 770-488-7946) Jennifer Taylor (vjf6@cdc.gov 770-488-7893) Golriz Yazdanpanah ( czu1@cdc.gov 770-488-7893)