RHD*weak D type 38: a family study
نویسندگان
چکیده
he RHD gene is responsible for the expression of the D antigen hile RHCE encodes proteins carrying antigens C or c, and E r e. RHD is present or absent depending on the RH haplotype, nd RHCE displays four common alleles (ce, Ce, cE, CE) responible for the expression of the two antithetical (allelic) series f antigens. RHD gene deletion is the leading cause of the Dhenotype worldwide.1 Functional (antigen) variations in the h blood group system is determined by insertion/deletion, ingle nucleotide polymorphisms (SNPs), and gene conversion vents in the RHD and RHCE genes. A weak D type is a variant f the RhD protein that comprises an amino acid substitution ocated in the transmembraneous or intracellular segments nd expresses a reduced amount of the D antigen [generally ess than 5000 D antigens per red blood cell (RBC)].2,3 The RHD*weak D type 38 is produced by the single nucleotide hange (833G>A) in the exon 6, causing a Gly278Asp substituion in the transmembraneous RhD protein. This RHD allele hows reduced expression of the D antigen on the RBC surace and may be erroneously typed as D negative by standard erologic methods.4–6 The frequencies of weak D type 38 vary n different populations. The weak D type 38 was found in
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