Report of the First International Workshop on molecular blood group genotyping

Daniels, Geoff; Schoot, C. Ellen van der; Olsson, Martin L.

doi:10.1111/j.1423-0410.2005.00603.x

Cited by 52 publications

(42 citation statements)

References 17 publications

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“…As most countries have only one or a few laboratories carrying out this work, an international EQA scheme is required. The International Society of Blood Transfusion (ISBT) organized international workshops in molecular blood group genotyping in (Daniels et al, 2005, 2007). In the most recent workshop (2008), two plasma samples from pregnant D-negative women, one with a D-positive and one with a D-negative fetus, were distributed to 17 laboratories (14 from Europe, 1 each from Australia, Brazil and China).…”

Section: Quality Assurancementioning

confidence: 99%

Noninvasive prenatal diagnosis of fetal blood group phenotypes: current practice and future prospects

et al. 2008

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Fetuses of women with alloantibodies to RhD (D) are at risk from hemolytic disease of the fetus and newborn, but only if the fetal red cells are D-positive. In such pregnancies, it is beneficial to determine fetal D type, as this will affect the management of the pregnancy. It is possible to predict, with a high level of accuracy, fetal blood group phenotypes from genotyping tests on fetal DNA. The best source is the small quantity of fetal DNA in the blood of pregnant women, as this avoids the requirement for invasive procedures of amniocentesis or chorionic villus sampling (CVS). Many laboratories worldwide now provide noninvasive fetal D genotyping as a routine service for alloimmunized women, and some also test for c, E, C and K.In many countries, anti-D immunoglobulin injections are offered to D-negative pregnant women, to reduce the chances of prenatal immunization, even though up to 40% of these women will have a D-negative fetus. High-throughput, noninvasive fetal D genotyping technologies are being developed so that unnecessary treatment of pregnant women can be avoided. Trials suggest that fetal D typing of all D-negative pregnant women is feasible and should become common practice in the near future.

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Section: Quality Assurancementioning

confidence: 99%

Noninvasive prenatal diagnosis of fetal blood group phenotypes: current practice and future prospects

et al. 2008

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“…The following steps were taken into account: i) Manual isolation protocol of cf-DNA from 800 μl of maternal plasma using the commercial QIAamp DNA Blood Mini kit which was compared to automated isolation of cf-DNA from 400 μl of maternal plasma using the Biorobot EZ1 workstation and the commercial EZ1 Virus Mini Kit v2. This comparison showed that automated extraction improved the yields of cf-DNA, so we consider it as a reliable method of cff-DNA isolation from maternal plasma for non-invasive fetal RHD genotyping (data not published); ii) In order to assess the quality of our approaches, we have participated in the International Workshop on Molecular Blood Group Genotyping since 2004 [13,14,36,37], as well as in the evaluation of the International Reference Reagent for the detection of RHD and SRY DNA in plasma performed by The National Institute for Biological Standards and Control (NIBSC) from UK plasma [29]; iii) Similarly, we have followed the recommendations for routine screening of the ) for the human RhDpositive male genomic DNA standard, and median values and ranges of detected genomic equi valent (GE)/ml (GE = 6.6 pg human DNA) of cf-DNA and cff-DNA in maternal plasma for the tested genes…”

Section: Discussionmentioning

confidence: 99%

“…The methodologies are based on a variety of quantitative realtime polymerase chain reaction (qPCR) protocols [10][11][12]. In order to resolve numerous technical issues regarding the RHD genotyping from maternal plasma, several studies and workshops have been performed, such as the International Workshop on Molecular Blood Group Genotyping (testing since 2004) and workshops under the auspices of the Special Advances in Fetal and Neonatal Evaluation (SAFE) Network of Excellence [13][14][15]. However, so far, only Denmark and the Netherlands have introduced fetal RHD typing in RhD-negative pregnant women as a routine screening program [16,17].…”

Section: Introductionmentioning

confidence: 99%

Reliable Determination of Fetal RhD Status by RHD Genotyping from Maternal Plasma

Dovč-Drnovšek

Klemenc

Toplak

et al. 2013

Transfus Med Hemother

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Background: Immunoprophylaxis with IgG anti-D is a standard prevention of hemolytic disease of the fetus and newborn. Fetal Rhesus D (RhD) blood group genotyping from maternal plasma of RhD-negative pregnant women allows targeted prophylaxis with IgG anti-D in RhD-positive pregnancies only. We set up a reliable protocol for prenatal RHD genotyping. Methods: 153 pregnant Caucasian RhD-negative women were tested in the 27th week (range 7–38th week) of pregnancy. 18 of them were alloimmunized to the RhD antigen. The fetal RHD genotype was determined based on an automated DNA extraction and real-time polymerase chain reaction method. Intron 4 and exons 5, 7 and 10 of the RHD gene and the SRY gene were targeted. Results: The fetal RhD status and gender was 100% correctly predicted in all 153 pregnancies (55 RhD-positive males, 45 RhD-positive females; 23 RhD-negative males, 30 RhD-negative females). Conclusion: The accuracy and applicability of our protocol for non-invasive fetal RhD determination allows the correct management of RhD-incompatible pregnancies. Our protocol could prevent unnecessary immunoprophylaxis in 53 of 153 cases. We therefore recommend that non-invasive fetal RHD genotyping is introduced as an obligatory part of prenatal screening.

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“…In 2004, the International Society of Blood Transfusion (ISBT) organized a workshop on molecular blood group genotyping. Thirty laboratories participated and the workshop culminated in a feedback meeting and was the precursor of an international quality assurance scheme [18]. Subsequently there have been ISBT workshops every second year, the year of the ISBT International Congress, with a feedback meeting at that congress [19][20][21].…”

Section: Workhops and External Quality Assurancementioning

confidence: 99%

Blood grouping by molecular genetics

Daniels

2011

ISBT Science Series

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It is possible to predict most clinically important blood group phenotypes from genomic DNA. Clinical applications include the following: determining foetal blood group to assess risk of haemolytic disease of the foetus and newborn or whether the pregnant woman requires antenatal anti-D prophylaxis; testing multiply transfused and autoimmune haemolytic anaemia patients; defining D variants; detecting donors with very weak D antigens; testing donors and patients when appropriate antisera are not available; RHD zygosity testing; zygosity testing of panel cells; assisting in solving difficult serological problems; and, with the use of highthroughput technologies, extended blood grouping of donors. Over the last 7 years, ISBT Workshops have provided external quality assurance. Future technologies may involve matrix-assisted laser desorption ⁄ ionization time-of-flight mass spectrometry and massively parallel (next generation) sequencing.Genes representing all of the 30 systems have been identified and sequenced and the molecular bases for almost all of the clinically significant blood group polymorphisms have been determined. This information makes it possible to predict a blood group phenotype from genomic DNA with a high degree of accuracy.Why use molecular techniques for determining blood group phenotype?There are three main reasons for using molecular methods, rather than serological methods, for red cell blood grouping: (1) when we need to know a blood group phenotype, but do not have a suitable red cell sample; (2) when molecular testing will provide more or better information than serological testing; and (3) when molecular testing is more efficient or more cost effective than serological testing. Clinical applications of molecular blood grouping Foetal genotypingA very important application is determination of foetal blood group in order to assess the risk of haemolytic disease of the foetus and newborn (HDFN). This is a noninvasive procedure carried out on cell-free foetal DNA in the maternal plasma, which represents 3-6% of the cellfree DNA in the plasma of a pregnant woman [1]. Currently the more usual application is in pregnant D-negative women with anti-D. If the foetus is D-positive it is at risk and the pregnancy should be managed appropriately; if it is D-negative it is not at risk and there is no need for any unnecessary interventions. The technology applied by most laboratories performing this testing is real time quantitative PCR to detect the presence or absence of RHD. Foetal DNA cannot be separated from maternal DNA, but the pregnant women being tested are D-negative and so will usually lack RHD. Consequently, any RHD detected must be of foetal origin and from a D-positive foetus; if no RHD is detected the foetus is considered to be D-negative. A quantitative PCR test is used to ensure that the RHD sequences detected are from the very small quantity of foetal DNA and not from the much larger quantity of maternal DNA. The assay must be designed so that

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Report of the First International Workshop on molecular blood group genotyping

Cited by 52 publications

References 17 publications

Noninvasive prenatal diagnosis of fetal blood group phenotypes: current practice and future prospects

Noninvasive prenatal diagnosis of fetal blood group phenotypes: current practice and future prospects

Reliable Determination of Fetal RhD Status by <b><i>RHD </i></b>Genotyping from Maternal Plasma

Blood grouping by molecular genetics

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