SCID disorder is major failure of the immune system, usually genetic. The aim of this study was on mutations detection of RAG1, RAG2, and IL7RG genes in SCID cases. Mutation detection was performed by PCR sequencing. Our results indicated that 13 mutations were found through cases which include 4 mutations in IL7R gene (T661I, I138V, T56A, C57W), 7 mutations in RAG1 (W896X, W204R, M324V, T731I, M1006V, K820R, and R249H), and 2 mutations in RAG2 gene (R229W, ΔT251).