title: [Result survey analysis of prenatal chromosome karyotyping in an external quality assessment program].
abstract: OBJECTIVE
  To analyze the results of prenatal karyotype of the external quality assessment program in 2013 in order to provide references and recommendations for improving the capability and performances of karyotype analysis of prenatal screening laboratories.
  
  
  METHODS
  Five lots of quality control cell photos were sent to 500 laboratories. The participants were asked to decide whether the photos have demonstrated any abnormal karyotype and determine the abnormal type. The results should be submitted before the deadline and compared with the standard results to evaluate the performances of the laboratory.
  
  
  RESULTS
  One hundred forty three laboratories have returned their karyotype results for the survey. The standard answers were 7,XX,+18, 46,X,i(X)(q10), 46,XY,i(21)(q10) or 46,XY,+21,der(21;21)(q10;q10), 46,XY and 47,XY,+21 in sequential order, which were used to estimate the score of each participant. The pass rates for five lots were 97.9%, 97.2%, 95.8%, 100.0% and 97.9%, respectively. The total pass rate was 97.7%. The error rates were 2.1%, 2.8%, 4.2%, 0 and 2.1%, respectively. The total error rate was 2.3%.
  
  
  CONCLUSIONS
  Some laboratories did not correctly identify the abnormal karyotypes, while some could not determine the right type of karyotype. The external quality assessment program of prenatal diagnosis of karyotype analysis should be conducted annually in order to improve the capability and performances of karyotype analysis of prenatal screening laboratories.
authors.affiliation: Chinese National Center for Clinical Laboratories, Beijing Hospital of the Ministry of Health, Beijing 100730, P.R. China. zhiguo_w@sina.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Chen
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Kun
authors.initials: K
authors.lastname: Zhong
authors.forename: Falin
authors.initials: F
authors.lastname: He
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Liming
authors.initials: L
authors.lastname: Bao
authors.forename: Lin
authors.initials: L
authors.lastname: Zou
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000328:Adult; D002877:Chromosomes, Human / Q000235:genetics*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000235:genetics*; D005820:Genetic Testing / Q000379:methods / Q000592:standards*; D006801:Humans; D007621:Karyotyping / Q000379:methods / Q000592:standards*; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods* / Q000592:standards*; D055815:Young Adult