Here we report an 8 years old girl who had post natal growth deficiency, microcephaly, facial dysmorphism, partial syndactyly of the second and third toes, susceptibility to infections, leukocytosis, immunodeficiency, adenopathy, but now sign of telangiectasia, ataxia and in evolution developed malignancy. Chromosomal analysis showed anomalies. By combining clinical manifestations and laboratory findings including cytogenetic findings and taking in account the evolution of the patient, we sustain the diagnosis of Nijmegen Breakage Syndrome.