Academy of Medical Sciences of I.R. Iran Archives of Iranian Medicine 1029-2977 22 12 2019 12 01 Clinical Presentation of Ataxia-Telangiectasia 682 686 EN Soheila Alyasin Hossein Esmaeilzadeh Narjes Ebrahimi Seyed Hesamodin Nabavizadeh Hamid Nemati Journal Article 2018 09 26 2019 04 16 Background: Ataxia-telangiectasia is a multi-system disorder in which neurologic impairment and immune deficiency are observed. In the present study, patients with ataxia-telangiectasia were followed to provide information regarding clinical and immunological features. Methods: We report a case series of 18 patients diagnosed with ataxia-telangiectasia, who were referred to a tertiary center of clinical immunology from 2008–2018. Clinical presentations, medical records and lab data were observed during this period with a mean follow-up time of 4.57 ± 2.66 years. Results: The mean age of the patients was 10.92 ± 3.24 years (11 females and 7 males). Thirteen patients (72.22%) were from families with consanguinity. Ataxia was the most common clinical feature, observed in 18 (100%) patients. The predominant clinical presentations were tremor and oculocutaneous telangiectasia, observed in 14 (77.8%) patients; dysarthria and oculomotor apraxia, observed in 13 (72.2%) patients. Infections were recorded in 12 (70.6%) patients. Decreased IgG level and IgA levels were observed in 5 (33.3%) and 6 (40.0%) patients, respectively. Decreased B-cell number and T-cell number were noted in 7 (46.67%) and 11 (73.33%) patients, respectively. Three (16.7%) patients were diagnosed with acute lymphoblastic leukemia and two of them expired subsequently. Conclusion: Ataxia-telangiectasia is a progressive disease with no established therapy; so, it necessitates early diagnosis and follow-up of the patients. The presented clinical and immunological data in this study may help with diagnosis and management of the disease complications.