OBJECTIVETo develop chromosome abnormal karyotype quality control cell and to explore the external quality assessment (EQA) method for chromosome karyotype analysis.

METHODSThe chromosome abnormal karyotype quality control cells were prepared by EB virus (EBV) transfection of human B lymphocyte strain establishment and were distributed to participating labs for EQA test of chromosome karyotype analysis project at appointed time. The evaluation results were obtained through 4 grades scoring.

RESULTSSix kinds of chromosome abnormal karyotype quality control cells were initially developed, the karyotypes of which were 46,X, t(Y;5)(q12;q21), 46, XY, 15p +, 46, XX, t(13;18)(q12;q21), 46, X, r(Xp), 46,X,t(Y;Y), 46,XX,t(9;20)(p13;p13) respectively. In the external quality assessment, feedbacks from the participating labs on the sequencing results of the six kinds of quality control cells showed that the wholly overlapping rate were 82.1%, 92.0%, 84.6%, 80.8%, 86.2%, 74.1% and the wholly deviation rate were 10.7%, 8.0%, 11.5%, 19.2%, 13.8%, 18.5%. The overall wholly overlapping rate, partial overlapping rate, partial deviation rate and wholly deviation rate turned out to be 83.2%, 0.6%, 2.5% and 13.7% respectively.

CONCLUSIONThe misdiagnose rate of chromosome karyotype analysis is rather high and regular external quality assessment is necessary to achieve dynamic information and improve diagnosis quality.