Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Oncology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Division of Oncology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Am J Hum Genet. 2019 Sep 5;105(3):658-668. doi: 10.1016/j.ajhg.2019.07.020. Epub 2019 Aug 29.
Neuroblastoma is a cancer of the developing sympathetic nervous system. It is diagnosed in 600-700 children per year in the United States and accounts for 12% of pediatric cancer deaths. Despite recent advances in our understanding of this malignancy's complex genetic architecture, the contribution of rare germline variants remains undefined. Here, we conducted a genome-wide analysis of large (>500 kb), rare (<1%) germline copy number variants (CNVs) in two independent, multi-ethnic cohorts totaling 5,585 children with neuroblastoma and 23,505 cancer-free control children. We identified a 550-kb deletion on chromosome 16p11.2 significantly enriched in neuroblastoma cases (0.39% of cases and 0.03% of controls; p = 3.34 × 10). Notably, this CNV corresponds to a known microdeletion syndrome that affects approximately one in 3,000 children and confers risk for diverse developmental phenotypes including autism spectrum disorder and other neurodevelopmental disorders. The CNV had a substantial impact on neuroblastoma risk, with an odds ratio of 13.9 (95% confidence interval = 5.8-33.4). The association remained significant when we restricted our analysis to individuals of European ancestry in order to mitigate potential confounding by population stratification (0.42% of cases and 0.03% of controls; p = 4.10 × 10). We used whole-genome sequencing (WGS) to validate the deletion in paired germline and tumor DNA from 12 cases. Finally, WGS of four parent-child trios revealed that the deletion primarily arose de novo without maternal or paternal bias. This finding expands the clinical phenotypes associated with 16p11.2 microdeletion syndrome to include cancer, and it suggests that disruption of the 16p11.2 region may dysregulate neurodevelopmental pathways that influence both neurological phenotypes and neuroblastoma.
神经母细胞瘤是一种发生于发育中交感神经系统的癌症。在美国,每年约有 600-700 名儿童被诊断患有神经母细胞瘤,占儿童癌症死亡人数的 12%。尽管近年来我们对这种恶性肿瘤复杂遗传结构的认识有所提高,但罕见种系变异体的贡献仍未得到明确界定。在这里,我们对两个独立的、多民族队列中的大(>500kb)、罕见(<1%)种系拷贝数变异(CNV)进行了全基因组分析,这两个队列共包括 5585 名患有神经母细胞瘤的儿童和 23505 名无癌症的对照儿童。我们在神经母细胞瘤病例中发现了 16p11.2 染色体上的一个 550kb 缺失,该缺失明显富集(0.39%的病例和 0.03%的对照;p=3.34×10)。值得注意的是,这种 CNV 对应于一种已知的微缺失综合征,该综合征影响大约每 3000 名儿童中的 1 名,并导致包括自闭症谱系障碍和其他神经发育障碍在内的多种发育表型的风险。该 CNV 对神经母细胞瘤风险有很大影响,其比值比为 13.9(95%置信区间=5.8-33.4)。当我们将分析仅限于欧洲血统的个体以减轻人群分层造成的潜在混杂时,该关联仍然显著(0.42%的病例和 0.03%的对照;p=4.10×10)。我们使用全基因组测序(WGS)对 12 例配对的种系和肿瘤 DNA 中的缺失进行了验证。最后,对四个亲子三胞胎的 WGS 显示,该缺失主要是从头发生的,没有母系或父系偏向。这一发现将 16p11.2 微缺失综合征相关的临床表型扩展到癌症,并表明 16p11.2 区域的破坏可能会扰乱影响神经发育途径的功能,从而影响神经表型和神经母细胞瘤。