The genesis of all cancers results from an accumulation of mutations, constitutional and/or acquired when induced by external mutagenic factors. High-speed technologies for genome sequencing have completely changed the study of disease genetics, but with limited knowledge of the functional value of most genetic changes.
Here, we proposed an innovative individual approach by studying tissue samples from a young woman with an unusual association of breast cancer, polycythemia vera, and rheumatoid arthritis. We performed genomic analyses for copy number variations and point mutations on laser-microdissected tumor cells from the breast cancer, and on CD34
Using ONCOSCAN technology, we identified a constitutional pR988C, c2962C>T mutation of 
Our study opens a considerable field of application in the domain of constitutional genetics, to establish genetic links between cancers and other very different severe diseases.