Research findings on Branchio-oto-renal syndrome have been published in a scientific paper.
- Shin-ya Nishio
- 1 day ago
- 2 min read
A paper summarizing the clinical characteristics of cases registered in the Branchio-oto-renal syndrome patient registry has been published in the journal Acta Otolaryngologica.
In this study, genetic testing was performed on 169 Japanese patients with Branchio-oto-renal syndrome. Variants in the EYA1 gene were identified in 66.7% of patients, while variants in the SIX1 were detected in 17.9% of cases.
In addition, detailed analyses of clinical information clarified the frequency of each clinical manifestation. Hearing loss, preauricular pits, and branchial fistulae were the most common features. Notably, the study also revealed a relatively high prevalence of middle ear and inner ear malformations, which had previously been regarded as only secondary or supportive clinical findings.
Symptoms | All | EYA1 | SIX1 |
Fistulae | 80.1% | 88.7% | 47.4% |
Second branchial arch anomalies | 16.2% | 20.4% | 0% |
Renal anomalies | 27.8% | 19.2% | 0% |
Hearing loss | 93.3% | 95.6% | 80% |
Auricle anomalies | 33.6% | 29.6% | 13.3% |
External ear anomalies | 10% | 8.6% | 0% |
Middle ear anomalies | 63.8% | 64.3% | 16.7% |
Inner ear anomalies | 71.1% | 78.7% | 50% |
Furthermore, detailed findings regarding the types of hearing loss were clarified, as summarized in the table below.
Type of HL | All | EYA1 | SIX1 |
Asymmetrical HL | 26.7% | 35.5% | 5% |
Progressive HL | 43% | 39% | 52.9% |
Conductive HL | 15.1% | 11.4% | 0% |
Mixed HL | 38.6% | 41.2% | 5.9% |
Sensorineural HL | 32.7% | 36% | 70.6% |
In addition, the relationship between the types of middle and inner ear malformations and the types of hearing loss was investigated. This study was the first large-scale analysis in the world to demonstrate that the type of hearing loss varies according to the site of the malformation.
Middle ear anomalies alone | Inner ear anomalies alone | Middle + inner ear anomalies alone | No middle/inner ear anomalies | |
Conductive HL | 42.7% | 6.7% | 12.9% | 7.3% |
Mixed HL | 37.5% | 23.3% | 55.7% | 26.8% |
Sensorineural HL | 20.8% | 66.7% | 18.6% | 41.5% |
Normal | 0% | 3.3% | 12.9% | 24.4% |
The findings of this study demonstrated that detailed radiological evaluation of middle and inner ear malformations is useful not only for the diagnosis of Branchio-oto-renal syndrome, but also for explaining the type of hearing loss observed in affected patients. Furthermore, these results provide important insights that may contribute to the selection of appropriate treatment strategies for hearing loss.
Reference：
Goto SI, Sasaki A, Nishio SY, Morita SY, Ogasawara N, Kobayashi Y, Amano A, Shinkawa C, Oda K, Wada T, Ikezono T, Matsuda H, Fujisaka M, Nagai K, Yoshimura H, Kashio A, Nishiyama N, Ito T, Tajima S, Oka SI, Kaga K, Takeda H, Kobayashi M, Sano H, Arai Y, Nakanishi H, Koizumi H, Obara N, Yoshida T, Esaki T, Takeuchi K, Yamazaki H, Horie R, Ohta Y, Morimoto C, Uehara N, Naito Y, Maeda Y, Ishino T, Egusa K, Sugahara K, Teraoka M, Kondo E, Tsuchihashi N, Kihara C, Kanda Y, Nakamura T, Miyanohara I, Kondo S, Usami SI.
Hearing characteristics of Branchio-oto-renal syndrome in Japan.
Acta Otolaryngol. 2026 doi: 10.1080/00016489.2026.2635665. Online ahead of print.
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