Frequency of the GJB2 gene variations in patients with NSHI_
| Amino Acid | Nucleotide | Number of Alleles | Frequency (%) |
|---|---|---|---|
| E47X | 139G>T | 1 | 1.52 |
| R32C | 94C>T | 1 | 1.52 |
| G4D | 11G>A | 1 | 1.52 |
| W77X | 231G>A | 1 | 1.52 |
| 59stop | 176-191del16 | 1 | 1.52 |
| Q80R | 239A>G | 1 | 1.52 |
| S139N | 416G>A | 2 | 3.03 |
| 11stop | 30-35delG | 3 | 4.55 |
| 299-300delAT | 299-300delAT | 10 | 15.15 |
| 79stop | 235delC | 45 | 68.18 |
| Total | 66 | 100.00 |
Mutation status in pediatric cases of NSHI cases by pre-lingual or post-lingual onset of deafness_
| Mutation Status | Pre-lingual Deafness (≤3 years) | Post-lingual Deafness (>3 and <18 years) | χ2 Test | p Value |
|---|---|---|---|---|
| GJB2: | 44 (23.66%) | 5 (9.80%) | 4.683 | 0.031 |
| mtDNA A1555G/C1494T: | 18 (9.68%) | 7 (13.73%) | 0.695 | 0.404 |
Distribution of age of onset in patients with the GJB2 gene and mtDNA mutations_
| Mutation Status | Total | Age at Onset | χ2 Test | p Value | ||
|---|---|---|---|---|---|---|
| ≤1 year | >1 and ≤3 years | >3 years | ||||
| GJB2 gene | 49 | 32 (65.31%) | 11 (22.45%) | 6 (12.24%) | 13.383 | 0.001 |
| mtDNA mutations | 30 | 8 (26.67%) | 9 (30.00%) | 13 (43.33%) | ||
Mutation status in pediatric cases of NSHI categorized by age at onset of deafness_
| Mutation Status | Infants (n = 186) | Preschool (n = 21) | School Age (n = 30) | χ2 Test | p Value |
|---|---|---|---|---|---|
| GJB2: | 44 (23.66%) | 2 (9.52%) | 3 (10.00%) | 4.685 | 0.096 |
| mtDNA A1555G/C1494T: | 18 (9.68%) | 2 (9.52%) | 5 (16.67%) | 1.363 | 0.502 * Fisher’s exact test |
Sequence changes in GJB2 gene mutations in 263 NSHI patients_
| Amino Acid | Nucleotide | Number of Affected Alleles | Number of Alleles | Category | |
|---|---|---|---|---|---|
| Homozygous | Heterozygous | ||||
| V27I | 79G>A | 27 | 90 | 144 | polymorphism |
| E114G | 341A>G | 11 | 69 | 91 | polymorphism |
| V37I | 109G>A | 1 | 11 | 13 | polymorphism |
| I203K | 608T>C | 1 | 8 | 10 | polymorphism |
| T123N | 368C>A | 0 | 3 | 3 | polymorphism |
| G4D | 11G>A | 0 | 1 | 1 | missense |
| 11stop | 30-35delG | 1 | 1 | 3 | deletion/frameshift |
| R32C | 94C>T | 0 | 1 | 1 | missense |
| E47X | 139G>T | 0 | 1 | 1 | missense |
| 59stop | 176-191del16 | 0 | 1 | 1 | deletion/frameshift |
| W77X | 231G>A | 0 | 1 | 1 | missense |
| 79stop | 235delC | 15 | 15 | 45 | deletion/frameshift |
| Q80R | 239A>G | 0 | 1 | 1 | missense |
| 299-300delAT | 299-300delAT | 3 | 4 | 10 | deletion/frameshift |
| S139N | 416G>A | 1 | 0 | 2 | missense |
| T18I | 53C>T | 0 | 1 | 1 | novel sequence variation |
| D50N | 148G>A | 0 | 1 | 1 | novel sequence variation |
| Y38C | 203A>G | 0 | 1 | 1 | novel sequence variation |
| T86R | 257C>G | 0 | 1 | 1 | novel sequence variation |
| G160S | 478G>A | 0 | 1 | 1 | novel sequence variation |
Comparison of the degree of hearing loss between patients with the GJB2 gene and mtDNA mutations_
| Mutation Status | Total | Degree of Hearing Loss | χ2 Test | p Value | |||
|---|---|---|---|---|---|---|---|
| Mild | Moderate | Severe | Profound | ||||
| GJB2 gene | 49 | 3 (6.12%) | 5 (10.20%) | 9 (18.37%) | 32 (65.31%) | <0.001 * Fisher’s exact test | |
| mtDNA mutations | 30 | 1 (3.33%) | 15 (50.00%) | 0 (0.00%) | 14 (46.67%) | ||
Mutations status in pediatric cases of NSHI categorized by age at the first hospital visit_
| Mutation Status | Infants (n = 72) | Preschool (n = 54) | School Age (n = 70) | χ2 Test | p Value |
|---|---|---|---|---|---|
| GJB2: | 16 (22.22%) | 14 (25.93%) | 15 (21.43%) | 0.384 | 0.826 |
| mtDNA A1555G/C1494T: | 1 (1.39%) | 2 (3.70%) | 6 (8.57%) | 4.314 | 0.143 * Fisher’s exact test |
Comparison of the degree of hearing loss by grading standard of 22 patients with mtDNA mutations_
| Grading Standard | Degree of Hearing Loss | ||||
|---|---|---|---|---|---|
| Mild | Moderate | Moderate to Severe | Severe | Profound | |
| Guidelines [11] | 1 | 11 | ‒ | 3 | 7 |
| ISO-1964 a Compared with 4.0-8.0 kHz p <0.001. b Fisher’s exact test. | 5 | 6 | 5 | 1 | 5 |
| ISO-1997 | 1 | 8 | ‒ | 5 | 8 |
| 0.25-8.0 kHz | 0 | 6 | 7 | 2 | 7 |
| 1.0-4.0 kHz | 0 | 4 | 5 | 7 | 6 |
| 4.0-8.0 kHz | 0 | 0 | 0 | 7 | 15 |