PROLONGED EXPRESSION OF THE C-KIT RECEPTOR IN GERM-CELLS OF INTERSEX FETAL TESTES

Stem cell factor (SCF) and its receptor Kit encoded by the c-kit proto -oncogene are crucial for tile development and migration of primordial germ cells in rodents. The expression of Kit has been examined immuno histochemically in gonads obtained from five specimens of fetal tissue s with intersex conditions which included 45,X/46,XY mosaicism; androg en insensitivity syndrome; and 46,XY/iso(p)Y mosaicism. Individuals wi th such disorders of sexual differentiation and Y-chrornosome material carry a very high risk of developing testicular neoplasms. Fetal test icular germ cells of the intersex subjects expressed Kit at a later de velopmental age than controls, in which no Kit protein was detectable beyond the 15th week of gestation. This finding may indicate a disturb ance of the chronology of germ cell development, or it may suggest a c hange of the regulation of c-kit expression in subjects with disorders of gonadal development.