Functional properties of the more frequent GJB2 mutations as described in the literature. The effect on the degree of hearing impairment of these mutations in combination with a 35delG allele is also included
Mutation | Effect on hearing impairment (current study) | Functional properties | References |
---|---|---|---|
35delG | Mild to profound, with most patients showing severe or profound hearing impairment | No expression | 41 |
IVS1+1G>A | Significantly less severe compared with 35delG | No expression | 42 |
V37I | Significantly less severe compared with 35delG | Complete loss of channel activity | 43 |
W77R | No significant difference compared with 35delG | Complete loss of channel activity | 43– 46 |
V84L | Possibly associated with less severe hearing impairment | Conductance similar to wild-type CX26 | 43, 47 |
L90P | Significantly less severe compared with 35delG | Complete loss of channel activity | 41, 43, 48 |
V95M | No significant difference compared with 35delG | Conductance similar to wild-type CX26 | 47 |
delE120 | Significantly less severe compared with 35delG | Complete loss of channel activity | 43 |
R143W | No significant difference compared with 35delG | Conductance similar to wild-type CX26 | 47 |
R184P | No significant difference compared with 35delG | Complete loss of channel activity | 43, 48 |