Institute of Human Genetics, Technische Universität München, Munich, Germany.
Kinderklinik München Schwabing, Technische Universität München, Munich, Germany.
Gene. 2018 Jul 15;663:110-114. doi: 10.1016/j.gene.2018.04.027. Epub 2018 Apr 12.
Patients with Silver-Russell syndrome (SRS), a syndromic growth retardation syndrome, usually harbor an epimutation at chromosome 11p15 or a maternal uniparental disomy of chromosome 7. However, to date the genetic cause remains unknown in around 40% of SRS cases, suggesting genetic heterogeneity and involvement of other genes. We present a 4-year-old female patient with the clinical diagnosis of SRS and negative results in common genetic SRS diagnostics. Whole exome sequencing identified a de novo heterozygous 7.3 kb deletion on chromosome 12q14.3 including exon 1 and 2 of HMGA2. HMGA2 encodes an architectural transcription factor and has already been linked to body size variations in various genome-wide association studies and mouse models. Reviewing the literature, we found additional four patients with a phenotype of SRS harboring point mutations or structural variants involving HMGA2. We conclude that genetic testing of HMGA2 should be considered in routine diagnostics in patients with the suspicion of SRS.
患有 Silver-Russell 综合征(SRS)的患者是一种综合征性生长发育迟缓综合征,通常在染色体 11p15 上存在表观遗传突变,或在染色体 7 上存在母系单亲二体性。然而,迄今为止,大约 40%的 SRS 病例的遗传原因仍不清楚,这表明存在遗传异质性和其他基因的参与。我们介绍了一位 4 岁的女性患者,其临床诊断为 SRS,常见的遗传 SRS 诊断结果为阴性。全外显子组测序发现 12q14.3 染色体上存在一个新的杂合性 7.3kb 缺失,包括 HMGA2 的外显子 1 和 2。HMGA2 编码一种结构转录因子,已经在各种全基因组关联研究和小鼠模型中与体型变化有关。我们回顾了文献,发现另外 4 名具有 SRS 表型的患者,其 HMGA2 存在点突变或结构变异。我们得出结论,在怀疑患有 SRS 的患者的常规诊断中,应考虑对 HMGA2 进行基因检测。