BACKGROUND: Jr(a) (ISBT 901005) is a high-prevalence antigen unassigned to a blood group system. People lacking this antigen have been found in all populations studied but most commonly in Asians. Two recent reports established that ABCG2-null alleles encode the Jr(a-) phenotype and these studies provided the impetus to study other Jr(a-) individuals. STUDY DESIGN AND METHODS: Blood samples were part of our rare donor-patient collection. DNA was isolated and analyzed by standard techniques. RESULTS: In samples from 13 Jr(a-) study subjects, we found six alleles with nonsense nucleotide changes, three (c.784T, c.1591T, and c.337T) were novel. Twelve of the samples were homozygous for nonsense single-nucleotide polymorphisms (SNPs): eight were c.376T, two were c.706T, one was c.784T, and one was c.1591T. Each of these alleles predicts a truncated ABCG2 product, Gln126Stop, Arg236Stop, Gly262Stop, and Gln531Stop, respectively. One study subject was heterozygous for two nonsense SNPs: c.337C/T (Arg113Stop) and c.736C/T (Arg246Stop). CONCLUSIONS: Jr(a) is the sole antigen in the newly established JR blood group system (ISBT 032001). The previous ISBT designation (901005) is now obsolete. Since ABCG2null alleles define the Jr(a-) phenotype, an explanation for why no antithetical low-prevalence antigen to Jr(a) has been found, and also why anti-Jr(a) made by people with any of these JRnull alleles are mutually compatible has been determined. Based on our findings DNA-based genotyping can be developed to replace the serologic methods that are currently used to identify Jr(a-) blood donors.
BACKGROUND: Jr(a) (ISBT 901005) is a high-prevalence antigen unassigned to a blood group system. People lacking this antigen have been found in all populations studied but most commonly in Asians. Two recent reports established that ABCG2-null alleles encode the Jr(a-) phenotype and these studies provided the impetus to study other Jr(a-) individuals. STUDY DESIGN AND METHODS: Blood samples were part of our rare donor-patient collection. DNA was isolated and analyzed by standard techniques. RESULTS: In samples from 13 Jr(a-) study subjects, we found six alleles with nonsense nucleotide changes, three (c.784T, c.1591T, and c.337T) were novel. Twelve of the samples were homozygous for nonsense single-nucleotide polymorphisms (SNPs): eight were c.376T, two were c.706T, one was c.784T, and one was c.1591T. Each of these alleles predicts a truncated ABCG2 product, Gln126Stop, Arg236Stop, Gly262Stop, and Gln531Stop, respectively. One study subject was heterozygous for two nonsense SNPs: c.337C/T (Arg113Stop) and c.736C/T (Arg246Stop). CONCLUSIONS: Jr(a) is the sole antigen in the newly established JR blood group system (ISBT 032001). The previous ISBT designation (901005) is now obsolete. Since ABCG2null alleles define the Jr(a-) phenotype, an explanation for why no antithetical low-prevalence antigen to Jr(a) has been found, and also why anti-Jr(a) made by people with any of these JRnull alleles are mutually compatible has been determined. Based on our findings DNA-based genotyping can be developed to replace the serologic methods that are currently used to identify Jr(a-) blood donors.
Authors: Celina Montemayor-Garcia; Panagiota Karagianni; David A Stiles; Erika M Reese; Danielle A Smellie; Debrean A Loy; Kimberly Y Levy; Magdalene Nwokocha; Marina U Bueno; Jeffery L Miller; Harvey G Klein Journal: Transfusion Date: 2018-10-12 Impact factor: 3.157
Authors: J R Storry; L Castilho; G Daniels; W A Flegel; G Garratty; M de Haas; C Hyland; C Lomas-Francis; J M Moulds; N Nogues; M L Olsson; J Poole; M E Reid; P Rouger; E van der Schoot; M Scott; Y Tani; L-C Yu; S Wendel; C Westhoff; V Yahalom; T Zelinski Journal: Vox Sang Date: 2013-12-27 Impact factor: 2.144