In belgium the diagnosis of non-Hodgkin lymphoma is held annually in 54 children under 20 years. In the Ghent University Hospital was two Belgian children of the same farnilie diagnosed non-Hodgkin's Burkitt's lymphoma (BL), which appears to indicate that this family is possibly a predisposing or predisposing factor present. Are known to have familial cases of BL very rare. There is a strong association between BL and epsteinbarrvirus (EBV). Bl has two entities: either (1) endemic, predominantly in New Guinea and in Africa, with a strong association with EBV, or (2) sporadically, the association with EBV is lower. Both are two different clinical entities and have specific chromosomal and genetic abnormalities. Some described case reports of families with BL deal with endemic BL. Only one study from 1986 by Anderson et al., Describes an american family waarbei brother and sister had both BL. Insofar as is known, there are no European family described with BL. The aim of this study is to see if we can detect susceptibility genes in this family using whole genome sequecing (WGS). WGS As a relatively new technique, which has become more affordable in recent years, no single study has done similar research.