How rare is cisAB blood?

Objective To determine the distribution of cisAB and B( A) alleles and to investigate the relationship between their phenotypes and genotypes in Shanghai blood donors. Methods ABO subgroups were identified by standard serologic techniques in ABO typing discrepancy samples from all donors in Shanghai Blood Center( 1 716 442 non-repeated donors). PCR methods were used for exon 6 and 7 of these ABO subgroup samples; then PCR products were TA cloned and sequenced. cis-AB and B( A) samples confirmed by DNA sequencing were collected to do further data analysis and phenotype-genotype relation study. Results 71 cis-AB and B( A) samples were confirmed by sequencing. Calibrated phenotype rate was 8. 3 /100 000 after the omission was considered. Six known cisAB alleles cis-AB01,cis-AB02,cis-AB02,B( A) 02,B( A) 04,B( A) 06 were found. The frequency of B( A) 04 was highest( 1. 6/100 000) cisAB and B( A) allele frequencies and then B( A) 02( 0. 78 /100 000) and cis-AB01( 0. 66 /100 000). The corresponding phenotypes of these alleles included AxB, ABx,AintBx and A2B,besides the typical phenotypes A2Bx and B( A). Conclusion B( A) 04 is most common in the cisAB and B( A) alleles in Shanghai blood donors,and then B( A) 02 and cis-AB01. Different kinds of phenotypes can be involved in cisAB and B( A) subgroups,which makes identification complicated. DNA analysis may need to confirm the atypical phenotypes.

https://www.semanticscholar.org/paper/Study-on-cisAB-and-B(-A)-subgroups-in-Shanghai-Sh/cdda9d8dea6c86df8579c23ea02c90f1714eec64