Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 4 2015 10 20 457 461 EN Maryam Nourizadeh Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Stephan Borte Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden AND Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, Municipal Hospital St. Georg, Leipzig, Germany. MohammadReza Fazlollahi Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Lennart Hammarström Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden. Zahra Pourpak Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 19 2015 10 19 Severe combined immunodeficiency (SCID) represents a rare group of primary immunodeficiency disorders (PIDs), with known or unknown genetic alterations. Here, we report a new interleukin 2 receptor, gamma chain (IL-2RG) mutation in an Iranian SCID newborn.The patient was a 6-day old boy with a family history of PID. The child was screened using a molecular-based analysis for the assessment of T cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs). Moreover, a complete immunological evaluation and gene sequencing was performed.Results showed undetectable TREC but a high level of KREC copy numbers. Flow cytometric data indicated low numbers of T and NK cells, but elevated number of B cells. A novel substitution in IL2RG: c.675 C>A, leading to p.225 Ser>Arg was found. Based on the functional analysis, the mutation is predicted to be damaging. The patient was diagnosed as a T B+ NK X-linked SCID. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/594 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/594/544