| GENE | LOCUS or SYNDROME | AMINO ACID CHANGE | NUCLEOTIDE CHANGE | EXON | ETHNICITY (Number of families) | REFERENCES |
| KCNQ4 | DFNA2 | FS71 | 211del13 | exon 1 | Belgian (1) | Coucke 1999 |
| L274H | 821T>A | exon 5 | Dutch (1) | Van Hauwe 2000 | ||
| W276S | 827G>C | exon 5 | Dutch (1); Japanese (1); Dutch (1), Japanese (1) | Coucke 1999; Akita 2001; Van Camp 2002 | ||
| L281S | 842T>C | exon 6 | American (1) | Talebizadeh 1999 | ||
| G285C | 853G>T | exon 6 | American (1) | Coucke 1999 | ||
| G285S | G>A | exon 6 | French (1) | Kubisch 1999 | ||
| G321S | 961G>A | exon 7 | Dutch (1) | Coucke 1999 |