Naturally occurring anti‐PP1PK in a Chinese individual with p phenotype: A case based on compound heterozygosity including one novel allele

The null phenotype in P1PK blood group, known as "p," is extremely rare in the whole world. Individuals of p phenotype spontaneously form anti-PP1PK isoantibody. Here, we report a case of p phenotype with naturally occurring anti-PP1PK isoantibodies in a Chinese individual.Serology tests, containing alloantibodies screening and identification, were conducted to demonstrate the phenotype in P1PK blood group. The genotype of A4GALT gene was identified by haplotypes separation and sequencing.The serological assay demonstrated the p phenotype of the proband, presenting with 1:64 titer of anti-PP1PK . The sequencing data revealed a compound heterozygote consisting of A4GALT*P1.01 with c.343A>T and a novel allele based on A4GALT*01N.05 with an addition polymorphism c.100G>A. The sequence of the novel allele has been submitted to GenBank and the accession number OM912503 was assigned.Our study demonstrates a case of naturally occurring anti-PP1Pk in a Chinese individual with p phenotype, which is based on compound heterozygosity including one novel allele. As the proband is a young lady, monitoring the titer of anti-PP1PK and early initiation of medical intervention are essential after her pregnancy.