Development of the biomarker for th e clinical diagnosis of Diamond-Blackfan Anemia

一些钻石-黑粉贫血(DBA)患者的核糖体蛋白(RPS)编码基因发生突变。为了确定新的突变，我们调查了核糖体蛋白基因的大量缺失。我们发展了一种基于定量-聚合酶链式反应的简便方法，其中阈值周期与基因拷贝数相关。使用这种方法，我们能够诊断出27名日本患者中有7名拥有通过测序没有检测到的突变。所有缺失较大的患者都有生长迟缓表型。我们的研究数据表明，在日本的DBA患者中，RP基因的大量缺失构成了相当大的一部分。此外，我们的新方法可能成为筛选已知DBA基因拷贝数和严重表型生物标志物的有用工具。

Some of Diamond-Blackfan anemia(DBA) patients possess mutations in genes coding for ribosomal proteins(RPs). To identify new mutations, we investigated large deletions in the Ribosomal Protein genes. We developed an easy method based on quantitative-PCR in which the threshold cycle correlates to gene copy number. Using this approach, we were able to diagnose 7 of 27 Japanese patients possessing mutations that were not detected by sequencing. All patients with a large deletion had a growth retardation phenotype. Our study data suggest that large deletions in RP genes comprise a sizable fraction of DBA patients in Japan. In addition, our novel approach may become a useful tool for screening gene copy numbers of known DBA genes and biomarker of severe phenotype.