Recently, researchers have described a newly-discovered, heritable genetic cause of acute lymphoblastic leukemia (ALL), namely mutation of the gene ETV6.
Much like mutation of the gene BRCA marks people at risk to develop breast and ovarian cancers, identification of mutations in the gene ETV6 may allow doctors to predict the development of ALL, allowing increased monitoring and in the future, perhaps strategies to prevent the disease.
There are just over 30,000 cases of ALL diagnosed in the United States each year, with the majority of those cases being in children ages 2-5.
To answer the question, the group performed "whole exome sequencing" of family members to, effectively, take snapshots of each protein-producing gene in the chromosomes of these people predisposed to ALL.
The gene was involved in the development of blood cells. "Somatic" mutations of the gene, meaning mutations that are not present in the genome at birth but develop later, have previously been implicated in the development of blood cancers. In fact, somatic ETV6 translocation is the most common gene rearrangement in childhood leukemia.
This study was one of two new reports to show that "germline" mutation of ETV6, meaning abnormality that was heritable and present in the genome at birth, can also cause cancers. Unlike somatic mutation of the gene, it seemed as if the germline mutation puts the patient one important step closer to the development of leukemia from the time of birth.