The mutation frequency of MT-RNR1 m.1555A>G in familial probands was significantly higher than in sporadic patients (χ(2) test, P = 0.000), while there were no significant differences in the mutation frequencies of GJB2 and SLC26A4 between the familial and sporadic groups (χ(2) test, P > 0.05).
C1853237
Isolated cases