Fatemeh Taghizade Mortezaee1, Behnaz Esmaeli1, Mohsen Badalzadeh1, Mohsen Ghadami2, Mohammad Reza Fazlollahi1, Zahra Alizade1, Amir Ali Hamidieh3, Zahra Chavoshzadeh4, Masoud Movahedi5, Marzieh Heydarzadeh6, Mahnaz Sadeghi Shabestari7, Mahmoud Tavassoli8, Mohammad Nabavi9, Rasoul Nasiri Kalmarzi10, Zahra Pourpak11. 1. Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 2. Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 3. Hematology Oncology and Stem Cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran. 4. Department of Pediatrics, Mofid Children Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 5. Department of Allergy and Clinical Immunology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran. 6. Department of Pediatrics, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran. 7. Tuberculosis and Lung Research Center of Tabriz, Children Hospital ,Tabriz University of Medical Sciences, Tabriz, Iran. 8. Isfahan University of Medical Sciences, Isfahan, Iran. 9. Department of Allergy and Clinical Immunology, Rasool-e-Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. 10. Department of Pediatrics, Kurdistan University of Medical Sciences, Sanandaj, Iran. 11. Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Pourpakz@tums.ac.ir.
Abstract
BACKGROUND: Leukocyte adhesion deficiency type I (LAD-I) is a rare, autosomal recessive inherited immunodeficiency disease. LAD-I is caused by mutations in the ITGB2 gene and characterized by recurrent severe bacterial infections, as well as impaired wound healing with lack of pus formation. METHODS: In this study, we investigated ITGB2 gene mutations in 12 patients and their parents. Genomic DNA was extracted from whole blood samples. All coding regions of the ITGB2 gene were amplified using PCR and followed by direct sequencing. RESULTS: Genetic analysis revealed 12 different homozygous mutations, including six missense (c.382G>A, c.2146G>C, c.715G>A, c.691G>C, c.1777C and new c.1686C>A), two new nonsense (c.1336G>T and c.1821C>A), three-frame shift (c.1143delc, c.1907delA and new c.474dupC) and a splice site (c.1877+2T>C). Flow cytometry analysis of CD11/CD18 expression on neutrophils revealed defect in CD18 in all twelve cases (1.4% to 42%), CD11a in ten cases (0.1% to 26.7%), CD11b in nine cases (1.2% to 58.8%), and CD11c in all cases (0 % to 18.1%). The patients' parents were both heterozygous carriers. CONCLUSION: Our findings showed four new mutations in the ITGB2 gene. These results can be used for decisive genetic diagnosis, genetic counseling, as well as prenatal diagnosis for all patients who are suspended to LADI.
BACKGROUND:Leukocyte adhesion deficiency type I (LAD-I) is a rare, autosomal recessive inherited immunodeficiency disease. LAD-I is caused by mutations in the ITGB2 gene and characterized by recurrent severe bacterial infections, as well as impaired wound healing with lack of pus formation. METHODS: In this study, we investigated ITGB2 gene mutations in 12 patients and their parents. Genomic DNA was extracted from whole blood samples. All coding regions of the ITGB2 gene were amplified using PCR and followed by direct sequencing. RESULTS: Genetic analysis revealed 12 different homozygous mutations, including six missense (c.382G>A, c.2146G>C, c.715G>A, c.691G>C, c.1777C and new c.1686C>A), two new nonsense (c.1336G>T and c.1821C>A), three-frame shift (c.1143delc, c.1907delA and new c.474dupC) and a splice site (c.1877+2T>C). Flow cytometry analysis of CD11/CD18 expression on neutrophils revealed defect in CD18 in all twelve cases (1.4% to 42%), CD11a in ten cases (0.1% to 26.7%), CD11b in nine cases (1.2% to 58.8%), and CD11c in all cases (0 % to 18.1%). The patients' parents were both heterozygous carriers. CONCLUSION: Our findings showed four new mutations in the ITGB2 gene. These results can be used for decisive genetic diagnosis, genetic counseling, as well as prenatal diagnosis for all patients who are suspended to LADI.