We report a loss-of-function, germline, homozygous variant in the AIRE gene associated with APECED syndrome and a gain-of-function variant in mitogen-activated protein kinase kinase kinase 3 (MAP3K3), previously identified in patients with cerebral cavernous malformations (CCMs). The gene discussed is MAPK3; the disease is autoimmune polyendocrine syndrome type 1.