The remaining 13 patients have NOTCH1 mutation (n = 1) [19]; ALPS-Caspase10 (n = 1) [19]; CD137 deficiency (n = 1) [73]; interleukin-37 deficiency (n = 1) [19]; IPEX syndrome (n = 1) [93]; prolidase deficiency (n = 1) [62]; PRKCD deficiency (n = 1) [95]; MAGT1 deficiency (n = 1) [99]; and unspecified immune dysregulatory disease (n = 5) [40, 46, 52, 63]. Here, PEPD is linked to immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome.