Banerjee Soumee, Kshirsagar Pooja D, Mathur Ankit, Kulkarni Swati, Reddy T V
Rotary TTK Blood Centre, Bangalore Medical Services Trust, Bangalore, India.
Department of Transfusion Medicine, Indian Council of Medical Research - National Institute of Immunohaematology, Mumbai, India.
Transfus Med. 2025 Jun;35(3):297-303. doi: 10.1111/tme.13137. Epub 2025 Apr 3.
The Rh system is an extremely important blood group system with over 50 antigens, 5 of which (D, C, E, c and e) are considered most clinically significant. Rare Rh deficient phenotypes include D--, which is a blood group characterised by the lack of expression of C, c, E and e and exalted expression of the D antigen on the red cells due to mutations in both alleles of the RHCE gene. This is a multicentre approach to a case of the rare D-- phenotype.
A 56-year-old lady with bad obstetric history presenting with severe anaemia had to be evaluated for a panreactive antibody affecting cross-matching. On identifying a D-- phenotype by serology, a thorough family study was performed on 18 of her first and second-degree relatives. Three family members were also found to be of the rare phenotype, one of whom was pregnant. This relative was counselled appropriately and provided with an overview of her phenotype for her obstetric care team. Molecular analysis by QMPSF confirmed the serological findings. This case eventually became the motivation behind an institutional "rare donor" registry programme.
Serology revealed a panreactive antibody affecting cross-matches. Her Rh phenotype was D+, C-, c-, E-, e-, K-, k+. Molecular analysis on her and three family members suggested homozygous CE-D hybrid alleles causing the D-- phenotype: RHCE-D(3-9)-CE.
D-- is an uncommon phenotype and was found to occur in a cluster in this family. Like most difficult immunohematological cases, it mandated a multicentric and a multi-technique approach to resolve.
Rh系统是一个极其重要的血型系统，有超过50种抗原，其中5种（D、C、E、c和e）被认为在临床上最为重要。罕见的Rh缺失表型包括D--，这是一种血型，其特征是由于RHCE基因的两个等位基因发生突变，导致红细胞上C、c、E和e不表达，而D抗原高度表达。这是一个针对罕见D--表型病例的多中心研究。
一名有不良产科病史且患有严重贫血的56岁女性，因一种影响交叉配血的全反应性抗体而接受评估。通过血清学鉴定出D--表型后，对其18名一级和二级亲属进行了全面的家族研究。还发现三名家庭成员也具有这种罕见表型，其中一人怀孕。对该亲属进行了适当的咨询，并为其产科护理团队提供了其表型概述。通过QMPSF进行的分子分析证实了血清学结果。该病例最终成为机构“稀有供体”登记计划的推动因素。
血清学检查发现一种影响交叉配血的全反应性抗体。她的Rh表型为D+、C-、c-、E-、e-、K-、k+。对她和三名家庭成员的分子分析表明，纯合的CE-D杂交等位基因导致了D--表型：RHCE-D(3-9)-CE。
D--是一种罕见表型，在这个家族中呈聚集性出现。与大多数困难的免疫血液学病例一样，解决该问题需要多中心和多技术方法。
