Weak D and DEL alleles detected by routine SNaPshot genotyping : identification of four novel RHD alleles

Monique Silvy (1, 2) , Sophie Simon (1, 2) , Julia Gouvitsos (1, 2) , Julie Di Cristofaro (1, 2) , Virginie Ferrara (1, 2) , Jacques Chiaroni (1, 2) , Pascal Bailly (1, 2)

1 UAABC - Anthropologie Bio-Culturelle
2 EFS - Alpes-Méditerranée - Etablissement Français du Sang - Alpes-Méditerranée

BACKGROUND: Molecular RHD blood group typing is very efficient for managing donors and patients carrying any of the various molecular types of weak D and DEL. The purpose of the work was to develop a multiplex polymerase chain reaction (PCR) SNaPshot assay for simultaneous detection of weak D and DEL alleles that are prevalent in Europeans, Africans, and Asians. STUDY DESIGN AND METHODS: Preliminary profiling was carried out on single-nucleotide polymorphisms (SNPs) associated with 13 prevalent RHD alleles, that is, weak D Types 1, 2, 3, 4.0, 4.0.1, 4.1, 4.2, 5, 11, 15, and 17; RHD(IVS3 +1g>a); and RHD(K409K). Multiplex PCR was used to amplify six RHD regions encompassing 14 SNPs. Identification was obtained by incorporation of the complementary dye single base at the 3′-end of each probe-primer. A prospective analysis was then carried out on 152 blood samples from patients (n = 53) and donors (n = 88) with equivocal RhD serology and pregnant women (n = 11). RESULTS: After validation, our SNaPshot assay allowed direct genotyping of 82.9% of samples overall and 100% of samples harboring weak D Types 1, 2, 3, and 4.1 alleles. In the remaining 17.1% of samples overall, sequence investigation allowed accurate genotyping. In addition, four novel RHD alleles were identified, that is, RHD(S256P), RHD(L390L), RHD(F410V), and RHD(IVS4-2a>g). CONCLUSION: The SNaPshot assay described herein is a helpful supplementary tool for resolving doubtful RhD serology. By allowing accurate identification of weak D and DEL alleles this assay should allow better management of the donors and the patients genotyped weak D Types 1, 2, 3, and 4.1 who can receive D+ blood units.

Mots clés: Weak K; DEL alleles; SNaPshot genotyping; RHD alleles

Domaines: Anthropologie biologique

Monique Silvy, Sophie Simon, Julia Gouvitsos, Julie Di Cristofaro, Virginie Ferrara, et al.. Weak D and DEL alleles detected by routine SNaPshot genotyping : identification of four novel RHD alleles. Transfusion, 2011, 51, pp.401-411. ⟨10.1111/j.1537-2995.2010.02830.x⟩. ⟨halshs-00636096⟩