{{Rsnum
|rsid=121912763
|Gene=RHD
|Chromosome=1
|position=25303329
|Orientation=plus
|GMAF=0.0004591
|Gene_s=RHD
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(G;G)
|geno2=(G;T)
|geno3=(T;T)
}}{{omim
|id=111680
|rsnum=121912763
|variant=0003
}}{{ClinVar
|rsid=121912763
|Reversed=0
|FwdREF=T
|FwdALT=G
|REF=T
|ALT=G
|RSPOS=25303329
|CHROM=1
|GMAF=0.0005
|dbSNPBuildID=133
|SSR=0
|SAO=1
|VP=0x050260000a05040016110100
|GENEINFO=RHD:6007
|GENE_NAME=RHD
|GENE_ID=6007
|WGT=1
|VC=SNV
|CLNALLE=1
|CLNHGVS=NC_000001.11:g.25303329T>G
|CLNORIGIN=1
|CLNSIG=5
|Tags=PM;S3D;NSM;REF;ASP;VLD;KGPhase1;KGPROD;OTHERKG;LSD;OM
|CAF=0.9995; 0.0004591
|CLNACC=RCV000019287.26
|CLNDBN=RHD, WEAK D, TYPE I
|CLNSRC=ClinVar; OMIM Allelic Variant
|CLNSRCID=NM_016124.4:c.809T>G; 111680.0003
|COMMON=0
|Disease=RHD
}}

[[rs121912763]] is a polymorphism in the [[RHD]] gene known as weak Rh D, and formerly known as D(u). 

A total of 16 different molecular weak D types plus 2 alleles characteristic of partial D have been identified. Most, if not all, weak D phenotypes carry altered RhD proteins, suggesting a causal relationship. Genotyping of weak D may guide Rhesus-negative transfusion policy for such molecular weak D types that were prone to develop anti-D, and who risk transfusion reactions if transfused with Rh D positive blood.