Jairak Thongbut1,2, Loann Raud3,4, Claude Férec3,4,5, Charuporn Promwong2, Pornlada Nuchnoi1,6, Yann Fichou3,4. 1. Department of Clinical Microscopy, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand. 2. National Blood Centre, Thai Red Cross Society, Bangkok, Thailand. 3. Univ Brest, INSERM, EFS, UMR 1078, GGB, Brest, France. 4. Laboratoire de Génétique Moléculaire et d'Histocompatibilité, CHU Morvan, Brest, France. 5. Laboratory of Excellence GR-Ex, Brest, France. 6. Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.
Abstract
BACKGROUND: Molecular genetics of the Rh system has been extensively studied in Caucasians, Black Africans, East Asians, and Indians more recently. In this work, we sought to investigate the molecular basis of variant D expression in the Thai population, which remains unknown. MATERIALS AND METHODS: Blood samples from 450 Thai donors showing the variant D phenotype were collected. The RHD gene was analyzed by quantitative multiplex polymerase chain reaction of short fluorescent fragments and/or Sanger sequencing. RESULTS: The most frequent alleles in 200 D-negative and 121 DEL samples were the whole RHD gene deletion and the Asian DEL alleles, respectively. In 129 weak/partial D samples, 36 variant alleles were identified, including eight novel alleles. RHD*06.03, which is common in variant D samples from South China, is the most prevalent variant allele, followed by the recently reported Indian RHD*01W.150 allele. DISCUSSION: For the first time, a comprehensive overview of the nature and distribution of variant RHD alleles in Thailand is reported. It is a milestone to pave the way towards improvement of the current screening strategy to identify DEL donors accurately. The next step will be the design and implementation of a simple molecular test for screening the most frequent alleles, specifically in this population.
BACKGROUND: Molecular genetics of the Rh system has been extensively studied in Caucasians, Black Africans, East Asians, and Indians more recently. In this work, we sought to investigate the molecular basis of variant D expression in the Thai population, which remains unknown. MATERIALS AND METHODS: Blood samples from 450 Thai donors showing the variant D phenotype were collected. The RHD gene was analyzed by quantitative multiplex polymerase chain reaction of short fluorescent fragments and/or Sanger sequencing. RESULTS: The most frequent alleles in 200 D-negative and 121 DEL samples were the whole RHD gene deletion and the Asian DEL alleles, respectively. In 129 weak/partial D samples, 36 variant alleles were identified, including eight novel alleles. RHD*06.03, which is common in variant D samples from South China, is the most prevalent variant allele, followed by the recently reported Indian RHD*01W.150 allele. DISCUSSION: For the first time, a comprehensive overview of the nature and distribution of variant RHD alleles in Thailand is reported. It is a milestone to pave the way towards improvement of the current screening strategy to identify DEL donors accurately. The next step will be the design and implementation of a simple molecular test for screening the most frequent alleles, specifically in this population.
Authors: T H Müller; F F Wagner; A Trockenbacher; N I Eicher; W A Flegel; D Schönitzer; F Schunter; C Gassner Journal: Transfusion Date: 2001-01 Impact factor: 3.157