Olga O. Blumenfeld & Santosh K. Patnaik Departments of Biochemistry (OOB) & Cell Biology (SKP) Albert Einstein College of Medicine, New York Phenotypes in the World of Blood Group Antigens documented in the Database of DNA Variation in Genes Encoding Blood Group Antigens

Blood Group Antigens proteins, glycans or glycolipids variety of functions expressed at the surface of red cells polymorphic in the population Y Y Y

Blood Group System A set of variant antigens resulting from alleles of a single locus, each defining a common serological phenotype.

Summary: 29 blood group systems, 40 genes, 707 alleles Also detailed: non-human counterparts for H/h, MN, Rh SystemLocusFuncionAlleles ABOABO enzyme115 Chido- Rodgers C4A, factor7+ C4B ColtonAQP1 channel 7 CromerDAF receptor13 DiegoSLC4A1exchanger 78 DombrockDOunknown9 DuffyFYreceptor7 Gerbich (Ge)GYPCstructure9 GILAQP3channel2 H/hFUT1,enzymes57 FUT2 IGCN2enzyme8 (IGnT) Indian (IN)CD44adhesion2 JMH SEMA7A signaling 0 Kell (with Kx)KEL,enzyme67 XK KiddSLC14A1transport8 KnopsCR1receptor24+ SystemLocusFunctionAlleles Landsteiner-ICAM4adhesion3 Weiner(LW) LewisFUT3,enzymes36 FUT6, FUT7 LutheranLUadhesion16 MNSGYPA,unknown43 GYPB, GYPE OKBSGadhesion5 P-relatedA4GALT,enzymes27 B3GALT3 RAPH-MER2 CD151 3 RhRHCE,transport126 RHD, RHCG RHAG, RHBG SciannaERMAPadhesion4 XgXG,adhesion0 CD99 (MIC2) YTACHEenzyme4

Summary of DNA alterations

Phenotype vs genotype A number of alleles give rise to the same blood group phenotype Silencing mutations nonsense, deletions, insertions, splicing, regulatory regions rearrangements, gross deletions (null phenotype in nearly all systems) Kell, Rh, Diego, ABO, others Gene rearrangements GYPA, Rh ex. Sta - 7 genotypes; RH neg - 17 genotypes A single allele gives rise to a unique blood group phenotype Missense mutations Kell, Diego, RH, Duffy, ABO and others Gene rearrangements GYPA, Miltenberger series; Rh, weak D(Du), DAU & others

Same Blood Group Phenotype, Multiple Genotypes Kell null 1 phenotype 11 genotypes 7 nonsense 3 splicing 1 deletion

Same Blood Group Phenotype, Multiple Genotypes O gene-null Same deletion in many alleles (261delG in 38 of 43 O null alleles)

19 variants Popov et al. JBC.1997,272,18325 Band 3 Glycoprotein del 19 blood group phenotypes 54 other phenotypes (spherocytosis, etc.) anion exchanger anion ex. Binds to rbc cytoskeleton

Diego 19 of 19 alleles Multiple Blood Group Phenotypes, Multiple Genotypes

Sites and distribution of alterations vs location of epitopes: Kell (KEL) Each polymorphic site can be assigned to a different Kell antigen 24 missense mutations at positions in extracellular domains 7 nonsense; 3 splicing ;1 del Sets of polymorphic residues Each expressed in different individuals at different frequencies. Common phenotype K-1, 2*; -3, -21, 4*; -6, 7*; 11*, -17; 14*, -24; 10, 5, 12, 13, 16, 18, 20, 22, -23 Known antithetical partners K2/K1; K4/K3/K21; K7/K6; K11/K17

The Kell Glycoprotein

Single Blood Group Phenotype, Single Genotype Kell 22 of 24 alleles note

Same Blood Group Phenotype, Multiple Genotypes: Examples in the KEL blood group system

Single Blood Group Phenotype, Single Genotype Rh

Examples of genotypes vs phenotypes due to DNA rearrangements in GYPA family Gene Sequence Phenotype GYPA ex3 EET ex4 GERVQLwild type GYPB ex2 QTN ex4 GETGQLwild type s GYPB ex2 QTN ex4 GEMGQL wild type S hyb.A-Bs Recombinationex3 EET ex4 GETGQL HIL hyb.A-BS Recombination ex3 EET ex4 GEMGQL SJL hyb.BAB Gene conversion ex3 EET ex4 GETGQL HIL hyb.B-A Recombination ex2 QTN ex4 GERVQL Sta Johe,Vengelen-Tyler,Leger,Blumenfeld Blood 1991,78:2456

Examples were provided showing that, on the red cell surface, single amino acid or carbohydrate alterations, resulting from missense mutations or other DNA changes are recognized, as one might expect, as foreign by the immune system and, remarkably, can be detected by serological approaches.

Acknowledgements Contributors to the database Departments of Biochemistry and Cell Biology, Albert Einstein College of Medicine Thank you!