Anti-Human Glycophorin A monoclonal antibody

Population data studies were carried out on a Caucasian population from North-East Spain (n = 129-292 individuals) for 13 PCR-based polymorphic DNA loci: six short tandem repeat loci (HumTH01,HumTPOX, HumCSF1PO, HumF13A01, HumFES/FPS, HumvWFA31), the six PM loci (HLA-DQ alpha, LDLR, GYPA, HBGG, D7S8, GC) and one variable number tandem repeat locus (D1S80). The genotypes distributions were in accordance with Hardy-Weinberg expectations. The combined use of the 13 polymorphic systems provides a high power of discrimination and power of exclusion for use in forensic casework and paternity testing.

BACKGROUND The MNS blood group system is defined by three homologous genes: GYPA, GYPB, and GYPE. GYPB encodes for glycophorin B (GPB) carrying S/s and the "universal" antigen U. RBCs of approximately 1% of individuals of African ancestry are U- due to absence of GPB. The U- phenotype has long been attributed to a deletion encompassing GYPB exons 2 to 5 and GYPE exon 1 (GYPB*01N). STUDY DESIGN AND METHODS Samples from two U-individuals underwent Illumina short read whole genome sequencing (WGS) and Nanopore long read WGS. In addition, two existing WGS datasets, MedSeq (n = 110) and 1000 Genomes (1000G, n = 2535), were analyzed for GYPB deletions. Deletions were confirmed by Sanger sequencing. Twenty known U- donor samples were tested by a PCR assay to determine the specific deletion alleles present in African Americans. RESULTS Two large GYPB deletions in U- samples of African ancestry were identified: a 110 kb deletion extending left of GYPB (DEL_B_LEFT) and a 103 kb deletion extending right (DEL_B_RIGHT). DEL_B_LEFT and DEL_B_RIGHT were the most common GYPB deletions in the 1000 Genomes Project 669 African genomes (allele frequencies 0.04 and 0.02). Seven additional deletions involving GYPB were seen in African, Admixed American, and South Asian samples. No samples analyzed had GYPB*01N. CONCLUSIONS The U- phenotype in those of African ancestry is primarily associated with two different complete deletions of GYPB (with intact GYPE). Seven additional less common GYPB deletion backgrounds were found. GYPB*01N, long assumed to be the allele commonly encoding U- phenotypes, appears to be rare.