Lindsay E A, Greenberg F, Shaffer L G, Shapira S K, Scambler P J, Baldini A
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Am J Med Genet. 1995 Mar 27;56(2):191-7. doi: 10.1002/ajmg.1320560216.
DiGeorge anomaly (DGA) and velo-cardiofacial syndrome (VCFS) are frequently associated with monosomy of chromosome region 22q11. Most patients have a submicroscopic deletion, recently estimated to be at least 1-2 Mb. It is not clear whether individuals who present with only some of the features of these conditions have the deletion, and if so, whether the size of the deletion varies from those with more classic phenotypes. We have used fluorescence in situ hybridization (FISH) to assess the deletion status of 85 individuals referred to us for molecular analysis, with a wide range of DGA-like or VCFS-like clinical features. The test probe used was the cosmid sc11.1, which detects two loci about 2 Mb apart in 22q11.2. Twenty-four patients carried the deletion. Of the deleted patients, most had classic DGA or VCFS phenotypes, but 6 deleted patients had mild phenotypes, including 2 with minor facial anomalies and velopharyngeal incompetence as the only presenting signs. Despite the great phenotypic variability among the deleted patients, none had a deletion smaller than the 2-Mb region defined by sc11.1. Smaller deletions were not detected in patients with particularly suggestive phenotypes who were not deleted for sc11.1, even when tested with two other probes from the DGA/VCFS region.
迪乔治综合征（DGA）和腭心面综合征（VCFS）常与22q11染色体区域单体性相关。大多数患者存在亚显微缺失，最近估计至少为1 - 2兆碱基对。目前尚不清楚仅表现出这些病症部分特征的个体是否存在该缺失，若存在，其缺失大小是否与具有更典型表型的个体不同。我们使用荧光原位杂交（FISH）技术对85名因分子分析转诊至我们这里的个体进行了缺失状态评估，这些个体具有广泛的类似DGA或类似VCFS的临床特征。所用的检测探针是黏粒sc11.1，它可检测22q11.2中相距约2兆碱基对的两个位点。24名患者存在该缺失。在这些存在缺失的患者中，大多数具有典型的DGA或VCFS表型，但有6名存在缺失的患者具有轻度表型，其中2名仅表现为轻微面部异常和腭咽功能不全。尽管存在缺失的患者之间表型差异很大，但没有一个患者的缺失小于sc11.1所定义的2兆碱基对区域。在未被sc11.1检测出缺失但具有特别提示性表型的患者中，即使使用来自DGA/VCFS区域的另外两种探针进行检测，也未检测到更小的缺失。
