Severe combined immunodeficiency (SCID) is the most serious primary or congenital human immunodeficiency disorder. It is a group of congenital disorders in which the immune system does not work properly. Children with SCID are vulnerable to recurrent severe infections, retarded growth, and early death. SCID, Athabascan type, is a type of SCID characterized by severe and recurrent infections, diarrhea, failure to grow at the expected rates of height and weight, ulcerating sores, low white blood cell counts, small lymph nodes, and cell sensitivity to ionizing radiation. SCID, Athabascan type, is caused by pathogenic variants in DCLRE1C gene.