Monosomy 12p in a radiation-induced germ cell tumor.

We report results of cytogenetic analysis of a cell line established from a radiation induced germ cell tumor. Tumors of this type are rare, and there is only one other report of chromosome analyses of solid tumors induced by radiotherapy (Cowan et al., 1990). The cells were grown for over a year, and harvested at passage 13. The karyotype was pseudodiploid, with several balanced translocations. Spontaneously occurring germ cell tumors are associated with i(12p). We did not observe an i(12p), but instead found monosomy of 12p and 7q22----q32.