Fig. 10. Human GJB2 heterozygote carriers have hearing sensitivity, and active cochlear amplification increased.

(A) GJB2 sequence from a heterozygote carrier shows a heterozygous c.109G > A mutant at the antisense strand. Top: GJB2 sequence from a normal subject. (B) Increased DPOAE in GJB2 heterozygote carriers. Normal hearing developmental children without mutations served as control. The DPOAE was recorded at I₁/I₂ = 65/55 dB SPL. *P < 0.05 and **P < 0.01, two-tailed t test. (C) GJB2 heterozygote carriers have large ABR waves. ABR was evoked by 25 dB of nHL. The traces of ABR recorded from different individuals were averaged. Error bars represent SEM. Apparent increases are visible at ABR peaks I, III, VI, and V recorded from GJB2 heterozygote carriers. (D) Quantitative measurements of ABR increase in GJB2 heterozygote carriers. The amplitude (peak-to-peak value) of each peak in individual recordings was measured and averaged. The ABR peaks I, VI, and V recorded from GJB2 heterozygote carriers were significantly increased in comparison with the normal control group. *P < 0.05 and **P < 0.01, one-way ANOVA with a Bonferroni correction. n.s., not significant.