Table 1. Characteristics of the study group: all examined patients with hearing loss (HL), and the 34 patients identified as having the m.3243A>G mutation.
| Studied patients | m.3243A>G mutation carriers | |
| Number | 1482 | 34* |
| Males | 649 (44%) | 13 (38%) |
| Females | 833 (56%) | 21 (62%) |
| Mean age at the study (years) | 5–62, mean 27.0 | 6–61, mean 31.0 |
| Mean age of onset of HL (years) | 5–40, mean 15; SD = 10.4 | 8–63, mean 261 SD = 13.7; N = 29*** |
| Profound degree of hearing loss** | 3.8% | 3.4% |
| Severe degree of hearing loss** | 6.6% | 13.8% |
| Moderate degree of hearing loss** | 43.6% | 51.8% |
| Mild degree of hearing loss** | 46% | 31% |
| Normal hearing | 0 | 5 |
| Other dysfunction of the inner ear (tinnitus/vertigo) | 399/103; (27%/7%) | 12/5; (35%/15%) |
| Progression of hearing loss during observation | ND | 14 |
| Positive family history of hearing loss | 528 (35.6%) | 33 (97.0%)2 |
| Development of additional multi-organ 3243A>G pathology | ND | 17 |
| Number of 35delG GJB2 heterozygotes | 80 (5.5%) | 1/16 (6.3%) |
*
16 probands and 18 relatives.
**
Arithmetic mean of 0.5, 1, 2 and 4 kHz for the better-hearing ear.
***
N = number of patients; 29 of 34 had HL; 5 subjects (aged 6–20) had normal hearing.
1
p<0.000001 vs patients without m.3243A>G (t-test).
2
p<0.00001.
ND = no data.