Department of Surgery, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), San Raffaele Scientific Institute, Milan, Italy.
Translational Cancer Biology Program, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland.
Mol Genet Genomic Med. 2020 Sep;8(9):e1389. doi: 10.1002/mgg3.1389. Epub 2020 Jun 26.
Milroy-like disease is the diagnostic definition used for patients with phenotypes that resemble classic Milroy disease (MD) but are negative to genetic testing for FLT4. In this study, we aimed at performing a genetic characterization and biochemical analysis of VEGF-C variations found in a female proband born with congenital edema consistent with Milroy-like disease.
The proband underwent next-generation sequencing-based genetic testing for a panel of genes associated with known forms of hereditary lymphedema. Segregation analysis was performed on family members by direct sequencing. In vitro studies were performed to evaluate the role of a novel identified variant.
Two VEGF-C variations were found in the proband, a novel p.(Ser65Arg) and a pathogenic c.148-3_148-2delCA, of paternal and maternal origin, respectively. Functional characterization of the p.(Ser65Arg) variation in vitro showed alterations in VEGF-C processing.
Our findings reveal an interesting case in which biallelic variants in VEGF-C are found in a patient with Milroy-like lymphedema. These data expand our understanding of the etiology of congenital Milroy-like lymphedema.
Milroy 样疾病是用于诊断具有与经典 Milroy 病(MD)相似表型但 FLT4 基因检测为阴性的患者的诊断定义。在这项研究中,我们旨在对一名出生时患有先天性水肿的女性先证者中发现的 VEGF-C 变异进行遗传特征和生化分析,该先证者的表型与 Milroy 样疾病一致。
先证者接受了基于下一代测序的与已知遗传性淋巴水肿形式相关的基因组合的基因检测。通过直接测序对家族成员进行了分离分析。进行了体外研究以评估新鉴定的变异的作用。
在该先证者中发现了两种 VEGF-C 变异,一种是新型的 p.(Ser65Arg)和一种致病性的 c.148-3_148-2delCA,分别来自父本和母本。体外对 p.(Ser65Arg)变异的功能特征分析显示 VEGF-C 加工发生改变。
我们的发现揭示了一个有趣的病例,即 VEGF-C 的双等位基因变异存在于具有 Milroy 样淋巴水肿的患者中。这些数据扩展了我们对先天性 Milroy 样淋巴水肿病因的理解。