However, whole-exome sequencing revealed a thrombotic risk variant (T630I) in the <i>PROS1</i> gene encoding protein S. This missense variant is often reported in patients with thrombosis or protein S deficiency, and may result in a thrombotic predisposition in some situations, such as nephrotic syndrome. Here, PROS1 is linked to hereditary thrombophilia due to congenital protein S deficiency.