Looking for same values in more than one columns

I have a data frame with the next information

      Syndromes                                 Genes
0   1p36 microdeletion syndrome     RP11-34P13.7; CICP27; AL627309.1; RP11-34P13.1...
1   Cri du Chat Syndrome            ICMT; LINC00337; HES3; GPR153; ACOT7; RP1-202O...
...

I would like to know if there are some genes involve in more one syndromews.

Is there an easy approach to do that?