ABSTRACT
<p><b>OBJECTIVE</b>To investigate the application of ABO blood group genotyping in complicated ABO blood group type.</p><p><b>METHODS</b>Ten specimens of complicated ABO blood group were genotyped by sequence specific primer PCR (PCR -SSP), and confirmed by DNA sequencing and alignment. Six hundred and ten blood samples typed by ABO immunoassay were as control of genotyping.</p><p><b>RESULTS</b>Ten cases of complicated blood type were identified by high resolution PCR- SSP as rare ABO blood groups: cis-AB01 (3 cases), B(A)04 (2 cases), cisAB02, B(A)02, Bel03, Bw12 and Ael05, confirmed by DNA sequencing. Genotyping and serotype detected 610 cases ABO blood group were coincident, and the frequency of A, B, AB and O were as 28.69%, 27.54%, 8.2% and 35.57% respectively. According to the genotypes, the highest frequency subgroup was O1 (32.87%), the lowest was A2 (0.66%).</p><p><b>CONCLUSION</b>PCR -SSP could type the ABO blood group accurately, but also the sub-group of blood type. However, special designed high resolution PCR -SSP or DNA sequencing is needed to identify the complicated blood groups.</p>