title: A comprehensive investigation of RHD polymorphisms in the Chinese Han population in Xi'an.
abstract: BACKGROUND
  This study is a comprehensive analysis of RHD in D-negative phenotypes in saline, in Xi'an, Shanxi province, central China.
  
  
  METHODS
  DCcEe in saline was measured for each blood sample from every donor between January 2008 and June 2012 in the Xi'an Blood Centre, China. D-negative results were confirmed by an indirect antiglobulin test and further investigated by adsorption-elution as required. The initial step of molecular analysis was RHD zygosity testing. Then RHD was detected by a sequence-specific polymerase chain reaction system for RHD(1227G>A), weak D type 15, and RHD(711delC) alleles for the samples carrying at least one RHD. For the remaining non-identified samples, ten RHD exons were amplified using a previously widely used RHD coding region sequencing method. Some RHD/RHCE conversion alleles were identified while those remaining were submitted to direct sequencing.
  
  
  RESULTS
  Overall, 2,493 D-negative samples in saline were detected in a total of 890,403 donors (D-negative rate, 0.28%). Among the D-negative individuals, RHD deletion (d/d) was assessed in 1685 donors (67.59%). Non-functional RHD alleles were detected in 184 donors (7.38%), the most common being the RHD-CE(2-9)-RHD and RHD(711delC) alleles. Two new alleles were observed and family investigations were performed; RHD(1227G>A) DEL was detected in 516 individuals (20.70%), and weak D or partial D variants were identified in 108 donors (4.33%). The most common alleles were weak D type 15, D(VI) type 3 and D(V) type 2. Four new weak D alleles were noted, and two cases of RHD(1227G>A)/weak D type 15 heterozygosity were confirmed.
  
  
  CONCLUSIONS
  Currently, it seems to be difficult to observe any new RHD alleles in the Han Chinese population. D prediction in this population is easier because popular alleles are dominant, accounting for about 99.80% of alleles in D-negative people. Weak D types and partial D variants are rare and occur in approximately 0.01% of the population.
authors: Shaanxi Blood Centre, Xi'an, Shanxi, China.
authors: Shi-Hui
authors: SH
authors: Ye
authors: Shaanxi Blood Centre, Xi'an, Shanxi, China.
authors: Da-Zhou
authors: DZ
authors: Wu
authors: Shaanxi Blood Centre, Xi'an, Shanxi, China.
authors: Man-Ni
authors: MN
authors: Wang
authors: Shenzhen Blood Centre, Shenzhen, Guangdong, China.
authors: Xiao-Ying
authors: XY
authors: Wu
authors: Dalian Medical University, Dalian, Liaoning, China.
authors: Heng-Gui
authors: HG
authors: Xu
authors: Shaanxi Blood Centre, Xi'an, Shanxi, China.
authors: Hua
authors: H
authors: Xu
authors: Department of Transfusion, The Second People's Hospital of Shenzhen, The Second People's Hospital of Shenzhen, Guangdong, China.
authors: Chao-Peng
authors: CP
authors: Shao
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D044466:Asian People / Q000208:ethnology / Q000235:genetics; D001782:Blood Donors; D002681:China / Q000208:ethnology; D005260:Female; D017353:Gene Deletion; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012204:Rh-Hr Blood-Group System / Q000235:genetics*
chemical_list: D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen