A 10-year-old female with right oblique inguinal hernia was investigated to exclude an XY karyotype. Chromosome analysis of peripheral blood showed 46,XX,inv(13)(p13;q11). In vitro aneuploidy was observed in two cells: a) 46,XX,inv(13), inv(13); b) 47,XX, +inv(13). Her father and three sisters were carriers for inv(13). Herein the authors review briefly familial inv(13)'s and report a new variant involving breakpoints (p13;q11).