Constitutional de novo t(1;22)(p22;q11.2) and ependymoma

There is a body of evidence suggesting the presence of a tumor suppressor gene on chromosome 22 which plays a role in the pathogenesis of ependymomas. We report a patient with a de novo constitutional t(1;22)(p22;q11.2) who developed a malignant ependymoma at age 5. The patient is otherwise phenotypically normal. By fluorescence in situ hydridization (FISH) analysis, the chromosome 22 breakpoint has been localized to the region between the DiGeorge locus and BCR. Since NF2 and EWS are both distal to BCR, they are presumably not involved in this rearrangement. This patient may offer a unique opportunity to identify the chromosome 22 ependymoma tumor suppressor gene by cloning the translocation breakpoint.