Clinical and laboratory characteristics of a group of patients with ataxia-telangiectasia syndrome

Abstract

This study presents the clinical and laboratory data of 50 patients with ataxia-telangioectasia syndrome (AT) (Louis-Bar syndrome) treated at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology (Moscow, Russia) between 2012 and 2021. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation. We found that the patients experienced a significant diagnostic delay (the median delay in diagnosis was 4.5 years), although the first typical symptoms of AT were present at an earlier age (the median age was 1.5 years). The majority of patients showed laboratory signs of immunodeficiency, yet only 24% of the children developed severe infections. However, lung infections resulted in bronchiectasis in 16% of the patients and were the cause of death in 4/10 cases. Fifty-two percent of the patients had autoimmune complications, including interstitial lung disease and skin granulomas, and 24% of the patients developed malignant neoplasms. Of patients who underwent testing, 85% had KREC and/or TREC levels below the cutoff values used for neonatal screening of primary immunodeficiency disorders in Russia, which suggests that the majority of AT cases could be diagnosed by neonatal screening. Early diagnosis, multidisciplinary approach and high clinical suspicion for neoplastic manifestations are crucial for the successful management of AT.