Previous case studies of patients with CD59 dysfunction, such as those with germline PNH and congenital CD59 deficiency, noted early-onset neurological dysfunction in these patients (Haliloglu et al., 2015; Höchsmann and Schrezenmeier, 2015; Johnston et al., 2012; Karbian et al., 2018; Solmaz et al., 2020). Here, CD59 is linked to hyperinsulinemic hypoglycemia, familial, 4.