With the aim to identify the molecular etiology of polyendocrine autoimmune syndrome, WES studies were conducted on the DNA of an APS3 patient, leading to the identification of the compound heterozygous c.331C>T (p.Arg111Trp)/c.302C>T (p.Thr101Ile) variants of TIM-3. Here, HAVCR2 is linked to autoimmune polyendocrinopathy.