Table 1.
Mitochondrial DNA variants identified in this study
| Gene | Mutation | Homo/heteroplasmy | prelingual HL (N = 54) |
Late-onset HL (N = 80) |
Controls (N = 137) |
freq in controls (%) | Japanese (N = 672)a |
freq in Japanese (%) | conservation indexb | Previous reportc |
mtDBc M (N = 2704) |
freq in mtDB (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 12S rRNA | 663A > G | homoplasmy | 3 | 5 | 2 | 1.5 | 48 | 7.1 | 29/51 | yes | 86 | 3.2 |
| 709G > A | homoplasmy | 7 | 7 | 12 | 8.8 | 125 | 18.6 | 19/51 | yes | 444 | 16.4 | |
| 750A > G | homoplasmy | 54 | 80 | 137 | 100.0 | no data | no data | 49/51 | yes | 2682 | 96.7 | |
| 752C > T | homoplasmy | 0 | 0 | 9 | 6.6 | 17 | 2.5 | 44/51 | yes | 20 | 0.7 | |
| 827A > G | homoplasmy | 4 | 3 | 3 | 2.2 | 25 | 3.7 | 48/51 | yes | 54 | 2.0 | |
| 904C > T | homoplasmy | 1 | 0 | 0 | 0.0 | 0 | 0.0 | 48/51 | none | 0 | 0.0 | |
| 961insC | homoplasmy | 1 | 0 | 3 | 2.2 | 1 | 0.1 | 9/51 | yes | 37 | 2.0 | |
| 961delT+ Cn | both | 0 | 1 | 4(2)d | 2.9 | no data | no data | 9/51 | yes | no data | no data | |
| 1005T > C | both | 1 | 1(1) | 1 | 0.7 | 1 | 0.1 | 33/51 | yes | 7 | 0.3 | |
| 1009C > T | homoplasmy | 0 | 0 | 1 | 0.7 | 1 | 0.1 | 9/51 | yes | 2 | 0.1 | |
| 1041A > G | homoplasmy | 0 | 4 | 5 | 3.6 | 11 | 1.6 | 26/51 | yes | 14 | 0.5 | |
| 1107T > C | homoplasmy | 0 | 0 | 6 | 4.4 | 29 | 4.3 | 30/51 | yes | 34 | 1.26 | |
| 1119T > C | homoplasmy | 1 | 2 | 7 | 5.1 | 20 | 3.0 | 20/51 | yes | 26 | 1.0 | |
| 1382A > C | homoplasmy | 0 | 1 | 11 | 8.0 | 62 | 9.2 | 38/51 | yes | 65 | 2.4 | |
| 1438A > G | homoplasmy | 54 | 80 | 137 | 100.0 | 662 | 98.5 | 46/51 | yes | 2620 | 96.9 | |
| tRNASer(UCN) | 7501T > A | homoplasmy | 0 | 3 | 0 | 0.0 | 1 | 0.1 | 15/51 | yes | 1 | 0.0 |
Mitochondrial gene variants that met the criterion for association with hearing loss (HL) are underlined and in bold type. aData from the mtSNP database [48]. bBased on the results of the multiple alignment by ClustalW. See Additional File 1: Table S1 for information on the species used to calculate the sequence conservation. cUppsala mtDB database [50]. dEach number in parentheses indicates the number of individuals with a heteroplasmic variant.