Monosomy 21 seen in live born is unlikely to represent true monosomy 21: a case report and review of the literature.
Monosomy 21 seen in live born is unlikely to represent true monosomy 21: a case report and review of the literature.
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DOI：
10.1155/2014/965401
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发表时间：
2014-01-01
影响因子：
--
通讯作者：
Pszczola, Rosalynn
中科院分区：
文献类型：
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作者：
Burgess, Trent;Downie, Lilian;Pszczola, Rosalynn
我们报告一例新生儿，经外周血淋巴细胞常规染色体分析发现有完整的21号单体。用常规染色体和FISH分析对成纤维细胞的进一步研究发现了另外两个马赛克细胞系；一个含有环状染色体21，另一个含有双环染色体21。此外，对成纤维细胞的染色体微阵列分析(CMA)显示，染色体区域21q11.2q22.13存在马赛克重复，约45%的细胞显示近端长臂片段的三个副本，这与21号染色体存在马赛克环的环不稳定性一致。CMA还显示了8.8Mb末端片段(21q22.13q22.3)的完整单体。虽然该患者被初步诊断为21三体，但该患者也具有与21单体一致的表型特征，例如突出的内侧皱褶、宽阔的鼻桥、前倾的鼻孔、简单的耳朵和双侧重叠的五指，这些特征也可以出现在唐氏综合症患者中。患者在4.5个月大时死亡。这一病例强调了对暂时诊断为21号单体的患者，特别是在新生儿期发现的患者，使用多种组织类型和分子检测方法进行额外研究的必要性。
We report a case of a neonate who was shown with routine chromosome analysis on peripheral blood lymphocytes to have full monosomy 21. Further investigation on fibroblast cells using conventional chromosome and FISH analysis revealed two additional mosaic cell lines; one is containing a ring chromosome 21 and the other a double ring chromosome 21. In addition, chromosome microarray analysis (CMA) on fibroblasts showed a mosaic duplication of chromosome region 21q11.2q22.13 with approximately 45% of cells showing three copies of the proximal long arm segment, consistent with the presence of a mosaic ring chromosome 21 with ring instability. The CMA also showed complete monosomy for an 8.8Mb terminal segment (21q22.13q22.3). Whilst this patient had a provisional clinical diagnosis of trisomy 21, the patient also had phenotypic features consistent with monosomy 21, such as prominent epicanthic folds, broad nasal bridge, anteverted nares, simple ears, and bilateral overlapping fifth fingers, features which can also be present in individuals with Down syndrome. The patient died at 4.5 months of age. This case highlights the need for additional studies using multiple tissue types and molecular testing methodologies in patients provisionally diagnosed with monosomy 21, in particular if detected in the neonatal period.