Familial cases (a grandfather, a father and a daughter) of the EEC syndrome (ectrodactyly, ectodermal dysplasia and cleft lip/palate) are reported. All of them have a balanced reciprocal translocation (46,XY or XX, t(7;9) (q11.21;p12) or (46,XY or XX, t(7;9) (p11.2;q12)), but no other members of the family have either the EEC syndrome or chromosome abnormalities. This indicates that one of the chromosome sites 7q11.21, 9p12, 7p11.2 and 9q12 is a candidate for gene locus of the EEC syndrome.