Sequencing help to identify genes invoved in the development of childhood cancer. Inherited small changes in nucleotide sequence of important genes, large structural variants and copy number alterations in key genes increase the risk of developing diseases. To identify these risk genes, data from families with history of the diseas can be used. Cohorts enriched for the disease an large biobanks can also be used to study the association between the disease ans susceptibility genes. Rare variants can be identified through the sharing of affected individuals in the same family. Genes harboring multiple of these variants can also be identified using burden testing. Genome wide association can help identify common varaints that contributes to the disease risk in unrelated individuals. Identifying common and rare variants is beneficial to council families with the disease, aid diagnosis, and provide targets for new therapy.