Deep intronic point mutations of the KIT gene in a female patient with cutaneous clear cell sarcoma and her family.

Clear cell sarcoma (CCS) of tendons and aponeuroses is an aggressive neoplasm that is characterized by a pathognomonic translocation, t(12;22)(q13;q12), resulting in an EWSR1-ATF1 chimeric gene. We report for the first time a female patient with CCS exhibiting both EWSR1-ATF1 fusion transcripts and hereditary homozygous point mutations in introns 11 and 16 of the KIT gene. Her parents and two brothers each had heterozygous point mutations in intron 11 or intron 16 of the KIT gene. The functional significance of these germline deep intronic point mutations and their relationship to the pathogenesis of CCS are unclear. Future studies investigating KIT intron mutations in a larger cohort of CCS patients are warranted.