title: Classification of weak variants of blood-group A.
mesh_terms: D000017:ABO Blood-Group System; D002874:Chromosome Mapping; D014644:Genetic Variation; D006386:Hemagglutination Tests; D006801:Humans; D010641:Phenotype; D012463:Saliva / Q000276:immunology
chemical_list: D000017:ABO Blood-Group System