Molecular structures identified in serologically D negative samples of an admixed population

TRUCCO BOGGIONE C; LUJÁN BRAJOVICH M; TARRAGO M; BIONDI C; MUÑIZ DIAZ E; NOGUES N; COTORRUELO C

TRANSFUSION

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Baltimore; Año: 2014 vol. 54 p. 2456 - 2462

0041-1132

BACKGROUND: The D negative phenotype is mainly caused by the complete deletion of the RHD gene in Caucasians. However, a plethora of allelic variants have been described among D negative individuals from different ethnic groups. STUDY DESIGN AND METHODS: A cohort of 1314 routine serologically D negative samples from white Argentineans was studied by molecular methods. RESULTS: Among the 1314 D negative samples, 2.1% showed RHD-specific amplifications. One hybrid Rhesus box was detected in all D negative/RHD positive samples suggesting a hemizygous status. The RHDΨ was found in 0.7% of rr samples while DEL and null variants were detected in 16.7% of the D negative samples expressing C and/or E antigens. The variants associated with the C antigen were: 7 RHD-CE-Ds, 2 RHD(1-2)-CE(2-9)-D(10), 2 previously unreported RHD(329T>C)-CE(3-9)-D null allele, 1 RHD(M295I) and 1 new RHCE(1-2)- RHD(3361del11-10) null allele whereas those associated with the E antigen were: 5 RHD(46T>C) and 1 novel RHD(581insG) null allele responsible for a premature stop codon. CONCLUSIONS: The prevalence of D negative/RHD positive samples is higher than that observed in Europeans. More than 50% of the RHD alleles found were represented by RHDψ and RHD-CE-Ds showing the African contribution to the genetic pool of the admixed population analysed. Interestingly, three new alleles were found, two of them being hybrid structures between previously described RHD variants recombined with RHCE sequences. The knowledge of the RHD allele repertoire in our population allowed the implementation of reliable typing and transfusion strategies for a better management of patients and pregnant women.