Mutations in RAG1 and ADA genes in patients with severe combined immunodeficiency (SCID): report of new mutations

Severe combined immunodeficiency (SCID) is a rare and mortal disorder with X-linked and autosomal recessive inheritance. Many genes is related to the disease including ADA, RAG1, RAG2, Artemis, CD45, JAK3, IL7R which have different clinical presentation and T and B lymphocytes profile. In this study, we investigated gene mutations in suspected patients referred to the Children Medical Center Hospital, Department of Allergy & Clinical Immunology. Blood tests for patients showed T-B- profile, so we selected the genes that were responsible in T and B cell maturation (ADA, RAG1 and RAG2). According to our possibilities, we studied ADA and RAG1 genes in patients. We did the test by PCR and Sequencing method. Also total ADA activity (tADA) and its isoenzymes (ADA1 and ADA2) were estimated in patients. Our investigation showed two mutations in ADA gene and three in RAG1 gene. In this study, we offer a new protocol for investigation of RAG1 gene. This is the first study on diagnosis of SCID patients through genetic investigation in Iranian patients.