Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 24 2 2025 03 10 187 197 Mohsen Badalzadeh Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Maryam Soleimani Bavani Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Zahra Alizadeh Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Milad Mirmoghtadaei Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Leila Shakerian Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Seiamak Bahram Laboratoire d’ImmunoRhumatologie Moléculaire, plateforme GENOMAX, INSERM UMR_S 1109, Faculté de Médecine, Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), LabEx TRANSPLANTEX, Université de Strasbourg, Strasbourg, France AND Service d’Immunologie Biologique, Plateau Technique de Biologie, Pôle de Biologie, Nouvel Hôpital Civil, 1 place de l’Hôpital, Strasbourg, France Anne Molitor Laboratoire d’ImmunoRhumatologie Moléculaire, plateforme GENOMAX, INSERM UMR_S 1109, Faculté de Médecine, Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), LabEx TRANSPLANTEX, Université de Strasbourg, Strasbourg, France Raphael Carapito Laboratoire d’ImmunoRhumatologie Moléculaire, plateforme GENOMAX, INSERM UMR_S 1109, Faculté de Médecine, Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), LabEx TRANSPLANTEX, Université de Strasbourg, Strasbourg, France Leila Moradi Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Anahita Razaghian Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Division of Allergy and Clinical Immunology, Department of Pediatrics, Hakim Children's Hospital, Tehran University of Medical Sciences, Tehran, Iran Raheleh Assari Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran AND Pediatric Rheumatology Research Group, Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Masoud Movahedi Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Mansoureh Shariat Department of Immunology and Allergy, Children's Medical Center Hospital, Tehran University of Medical Sciences, Tehran, Iran Massoud Houshmand Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran Laleh Habibi Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Amir Hamidieh Pediatric Cell and Gene Therapy Research Center, Gene, Cell and Tissue Research Institute, Tehran University of Medical Sciences, Tehran, Iran Mahmoud Reza Ashrafi Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Mohammad Reza Fazlollahi Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran Zahra Pourpak Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Children's Medical Center Hospital, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran 2024 04 17 2024 09 24 Ataxia Telangiectasia (A-T) is a rare autosomal recessive neurodegenerative disease caused by mutations in the ataxia telengiectasia mutated (ATM) gene. The gene is on chromosome 11q22-23 and codes for the protein kinase ATM, which plays an essential role in DNA damage repair. In this study, we review the clinical characteristics of 13 A-T patients, 2 of whom displayed novel mutations. Thirteen patients with ataxia-telangiectasia from 10 unrelated families were referred to  Immunology, Asthma and Allergy Research Institute, Tehran, Iran. After clinical confirmation, blood samples were collected from the patients and their parents. Genetic analysis for 8 patients was conducted using whole-exome sequencing; in the other 3 patients, polymerase chain reaction was used, followed by sequencing. We identified 11 different mutations in the ATM gene. Two patients had mutations as compound heterozygous, while 9 other patients were homozygous for the mutations. Among these, 2 likely pathogenic mutations (ie, c.2639-1G>A and c.7940_7970del​TTCCAGCAGA​CCAGCCAATT​ACTAAACTTAA) have not been reported. Our study highlights the significance of next-generation sequencing techniques in identifying novel ATM mutations in A-T patients. Although all reported A-T mutations reside in 1 gene, the absence of a mutation hotspot for this gene necessitates the use of next-generation sequencing techniques. Specifically, we identified 2 mutations that have not been reported previously, emphasizing the importance of continued research in this area. This study provides new insights into the genetic underpinnings of A-T and underscores the potential clinical implications of identifying novel mutations. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/4083 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/4083/2162