TEK and blue rubber bleb nevus: BRBNS is usually caused by sporadic mutations in the TEK gene encoding the TIE2-angiopoietin endothelial tyrosine kinase receptor (Soblet et al., 2017; Mayba and Cullingham, 2019), but only a few germline mutations are located on chromosome 9p (Gallione et al., 1995; Wang et al., 2018).