Richard Martine, Perreault Josée, Constanzo-Yanez Jessica, Khalifé Samir, St-Louis Maryse
Héma-Québec, Research and Development, Quebec, Quebec, Canada.
Transfusion. 2007 May;47(5):852-7. doi: 10.1111/j.1537-2995.2007.01199.x.
A 28-year-old woman of Lebanese origin experienced two stillbirths. At the time, serology typed her red blood cells as being group A D- and found an anti-D in her serum sample. Molecular biology analysis, however, showed that she was in fact RHD+.
To better characterize this case, a full investigation including family members was undertaken. Classical serology techniques and DNA and RNA analysis were performed whenever possible.
Serology results showed that the patient's father and two brothers were D-. RHD genotyping demonstrated that her two brothers were indeed RHD+. Polymerase chain reaction (PCR) amplification was performed on each RHD 10 exons. Exon 8 did not amplify for the patient, her father, and her two brothers. Her mother and sister had exon 8. Messenger RNA analysis showed five RHD transcripts. The longest transcript was missing exon 8 but had a part of intron 7 inserted instead. Genomic DNA sequencing revealed a 995-bp deletion including part of intron 7, exon 8, and intron 8. This mutation, RHD(delEx8), was found to express a DEL in adsorption-elution. To facilitate the screening of this new DEL allele, a simple PCR-based assay was designed.
This novel allele represents the first observation of a large deletion at the genomic level within the RHD gene in Caucasian persons.
一名28岁的黎巴嫩裔女性经历了两次死产。当时，血清学检测将她的红细胞分型为A D-型，并在她的血清样本中发现了抗-D抗体。然而，分子生物学分析表明她实际上是RHD阳性。
为了更好地描述该病例，对包括家庭成员在内进行了全面调查。尽可能采用经典血清学技术以及DNA和RNA分析。
血清学结果显示患者的父亲和两个兄弟为D-型。RHD基因分型表明她的两个兄弟确实是RHD阳性。对每个RHD的10个外显子进行了聚合酶链反应（PCR）扩增。患者、她的父亲和两个兄弟的外显子8未扩增。她的母亲和姐姐有外显子8。信使RNA分析显示有5种RHD转录本。最长的转录本缺失外显子8，但插入了一部分内含子7。基因组DNA测序揭示了一个995碱基对的缺失，包括部分内含子7、外显子8和内含子8。这种突变，即RHD（delEx8），在吸附洗脱中表现为一种DEL型。为便于筛查这种新的DEL等位基因，设计了一种基于PCR的简单检测方法。
这种新的等位基因代表了在白种人中首次在基因组水平上观察到RHD基因内的大片段缺失。
