severe combined immunodeficiency, autosomal recessive, T cell-negative, B cell-negative, NK cell-positive (MONDO_0011086) is a rare, genetic T-B- severe combined immunodeficiency disorder due to null mutations in recombination activating gene (RAG) 1 and/or RAG2 resulting in less than 1% of wild type V(D)J recombination activity. Patients present with neonatal onset of life-threatening, severe, recurrent infections by opportunistic fungal, viral and bacterial micro-organisms, as well as skin rashes, chronic diarrhea, failure to thrive and fever. Immunologic observations include profound T- and B-cell lymphopenia, normal NK counts and low or absent serum immunoglobulins; some patients may have eosinophilia. Also known as: SCID due to complete RAG1-2 deficiency, SCID due to complete RAG1/2 deficiency, severe combined immunodeficiency due to complete RAG1-2 deficiency, severe combined immunodeficiency, B cell-negative.