CRACR2A and combined immunodeficiency: The identified calcium channelopathies encompass autosomal recessive loss-of-function (LOF) variants in STIM1, ORAI1, and CRACR2A, characterized by either early-onset severe combined immunodeficiency (SCID) or late-onset CID, accompanied by additional systemic manifestations including hypotonia, osteopetrosis, and anhidrotic ectodermal dysplasia (ED) with significant enamel defects (5–8).