title: Weak D type 42 cases found in individuals of European descent.
abstract: Patient samples were referred to our immunohematology reference laboratory to investigate the presence of a weak D antigen. In the last 3 years, 26 samples were received. Serology and molecular analyses were performed to identify the weak D variant. RHD mRNA from all patients was reverse transcribed, and cDNA was sequenced. The results were compared with a normal RHD sequence to identify the polymorphisms causing the weak D phenotype. Five different already known RHD variants were observed: weak D type 1 (5 individuals), weak D type 2 (1 individual), weak D type 42 (17 individuals), weak D type 45 (1 individual), and partial D DNB (2 individuals). Surprisingly, weak D type 42 was prevalent in our population, whereas weak D type 1, 2, and 3 are the most prevalent variants elsewhere. Anti-D was found in six cases of weak D type 42. The higher prevalence of weak D type 42 could be the result of a founder effect. Additional studies are needed to estimate the frequency of this variant in the general population.
authors.affiliation: Laboratoire de référence et des cellules souches, Héma-Québec, 1070, avenue des Sciences-de-la-Vie, Québec G1V 5C3, Canada.
authors.forename: Maryse
authors.initials: M
authors.lastname: St-Louis
authors.forename: Martine
authors.initials: M
authors.lastname: Richard
authors.forename: Marie
authors.initials: M
authors.lastname: Côté
authors.forename: Carole
authors.initials: C
authors.lastname: Ethier
authors.forename: Anne
authors.initials: A
authors.lastname: Long
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000915:Antibody Affinity; D001787:Blood Group Incompatibility / Q000097:blood* / Q000453:epidemiology; D001788:Blood Grouping and Crossmatching / Q000706:statistics & numerical data; D004252:DNA Mutational Analysis; D005260:Female; D018703:Founder Effect; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D011110:Polymorphism, Genetic; D015995:Prevalence; D011485:Protein Binding; D012204:Rh-Hr Blood-Group System / Q000235:genetics* / Q000276:immunology*; D044465:White People; D055815:Young Adult
chemical_list: D007518:Isoantibodies; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen