An analysis of RHD zygosity of Rh(D)-positive Chinese Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the RHD zygosity of Rh(D)-positive Chinese Hans in order to study the mother-fetus Rh isoimmunization prophylaxis.</p><p><b>METHODS</b>Rh(D) blood group of 31 115 donors were serotyped, and the RHD zygosities were analyzed, or determined through a PCR method for 3628 donors of Rh(D)-positive individuals.</p><p><b>RESULTS</b>Among the 31 115 donors, 99 were tested Rh(D)-negative by indirect antiglobulin test (IAT) (0.318%). The d frequency was 0.056 41, D was 0.943 59, and Dd heterozygosity was 0.106 45 (10.6%). However the rate was 0.090 32 (about 9.0%) after excluding DEL (IAT-negative). For the 3628 PCR tested donors, 3383 were DD (93.2%), 245 were Dd (6.8%). After excluding nonfunctional RHD alleles, 7.4% of the donors were carrying one functional RHD. It showed that an Rh(D)-negative Chinese Han woman gives an Rh(D)-negative child at a rate of 3.7%-4.5% when her husband is Rh(D)-positive.</p><p><b>CONCLUSION</b>Fetus Rh(D) genotyping may be unnecessary for Chinese Hans if invasive operation was needed for prenatal diagnosis. The Rh prophylaxis could be chosen assuming an Rh(D)-positive fetus.</p>

The family investigation of a weak D type 15 donor / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the genetic feature of weak D type 15 allele (RHD845A) in a Chinese family.</p><p><b>METHODS</b>Rh D, C, c, E and e phenotypes of 4 members in a weak D type 15 family were tested by serological and polymerase chain reaction (PCR), D antigen was proven by indirect antiglobulin test. A pair of primers specific for RHD845A were designed, and a sequence specific primer-PCR (PCR-SSP) method was established to detect RHD845A allele in all family members. Subsequently the dual-tube PCR method was used to determine the RHD zygosity of 4 members.</p><p><b>RESULTS</b>The RHD845A allele existed in all 4 family members and the RHD zygosity test showed that all members were RHD +/RHD + homozygous. The parents and nephew possessed one normal RHD gene as RHD845A allele carriers, which caused RhD positive. The proband and his old-sister took two RHD845A alleles, which caused weak D phenotype.</p><p><b>CONCLUSION</b>The proband is the weak D type 15 allele homozygous. The weak D type 15 gene is an ancestral allele, but not a mutation.</p>