Abstract
Nijmegen Breakage Syndrome (NBS) belongs to the group of primary immunodeficiency diseases associated with increased chromosomal instability. NBS is caused by mutation in NBN1 (formely NBS1) gene, the most frequent is so-called "Slavic" mutation c.657del5.
The disease manifests by congenital microcephaly, growth retardation, tendency to malignancies, radiosensitivity, variable defects of the immune system and hypergonadotropic hypogonadism. Here we present 4 case-reports of patients with NBS, 2 of them were diagnosed in infancy during the allergo-immunologic investigation, while the remaining 2 in the pubertal age after the development of malignant lymfoproliferative diseases.
Our observation shows the importance of early recognition of NBS, where the allergo-immunologic examination may play a crucial role.