摘要Background:Ataxia telangiectasia (AT) is a genetically based multisystemic disorder.We aimed to make a comprehensive evaluation of multisystem involvement in AT by describing clinical features and outcome of 91 patients.Methods:Medical records of the patients who were diagnosed and followed by a multidisciplinary approach during a 27-year period (1988-2015) were reviewed retrospectively.Results:Forty six female and 45 male patients with a mean follow-up period of 39.13±4.28 months were evaluated.The mean age at the time of symptom onset and diagnosis were 15.4±1.09 months and 73.6144.11 months,respectively.Neurological abnormalities were progressive truncal ataxia,nystagmus,dysarthria,oculomotor apraxia and choreoathetosis.Thirty one patients (34.1％) became dependent on wheelchair at a mean age of 12.1±2.8 years.Eleven patients (12.1％) became bedridden by a mean age of 14.7±1.8 years.Cranial magnetic resonance imaging revealed pathological findings in 47/66 patients.Abnormal immunological parameters were determined in 51/91 patients:immunoglobulin (Ig)A deficiency (n=38),lymphopenia (n=30),IgG (n=15) and IgG2 (n=11) deficiency.Occurrence of recurrent sinopulmonary infections (n=45) and bronchiectasis (n=22) were found to be more common in patients with impaired immunological parameters (P=0.029and P=0.023,respectively).Malignancy developed in 5 patients,being mostly lymphoreticular in origin and resulted in death of 4 patients.Conclusions:AT is a long lasting disease with muitisystem involvement necessitating multidisciplinary follow up,as described in our cohort.Early diagnosis of malignancy and supportive treatments regarding pulmonary and neurological health may prolong survival and increase the quality of life.