title: Markers for screening lynch syndrome are reliable and useful for identifying the specimen mislabeling.
abstract: BACKGROUND
  During specimen processing in surgical pathology laboratories, specimen-related adverse events (SRAEs), such as mislabeling and specimen mixed-up might occur. In these situations, molecular techniques using short tandem repeat (STR) loci are required to identify the personal identity. Microsatellite instability (MSI) test is widely used for screening the hereditary non-polyposis colon cancer (Lynch syndrome) in surgical pathologies using polymorphic STR markers. We tried to evaluate the applicability of the MSI test for SRAEs.
  
  
  METHODS
  We obtained 253 MSI test results to analyze the allele frequencies. After calibrating the estimated nucleotide lengths, we calculated the allele frequencies, a random match probability, and a likelihood ratio (LR) of three dinucleotide STR markers (D5S349, D17S250, and D2S123).
  
  
  RESULTS
  The distribution of LR was 136.38 to 5,606,213.10. There was no case of LR<100. In addition, there were 153 cases (60.5%) of LR ranging from 100 to 10,000 and 100 cases (39.5%) of LR>10,000. Furthermore, the combined probability of identity was 9.23×10(-4) and the combined power of exclusion was 0.99908.
  
  
  CONCLUSIONS
  Using the three STR markers that are recommended for MSI test, all the cases were positively identified in 1% range and about one-third cases showed high LR (>10,000). These results showed that MSI tests are useful to screen the personal identity in case of SRAE in pathology laboratories.
authors.affiliation: Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sun-Ju
authors.initials: SJ
authors.lastname: Byeon
authors.forename: Jiwoon
authors.initials: J
authors.lastname: Choi
authors.forename: Kyung Han
authors.initials: KH
authors.lastname: Nam
authors.forename: Bo-Gun
authors.initials: BG
authors.lastname: Jang
authors.forename: Hee Eun
authors.initials: HE
authors.lastname: Lee
authors.forename: Min A
authors.initials: MA
authors.lastname: Kim
authors.forename: Woo Ho
authors.initials: WH
authors.lastname: Kim
keywords: Biometric identification; Gene frequency; Microsatellite instability; Microsatellite repeats