Epidemiology

About 30% of the hereditary hearing loss patients suffer syndromic hearing loss with various associated symptoms. However, most of these disorders are rare and only limited clinical information is available. In Japan, nationwide epidemiological surveys of various hearing disorders, including juvenile onset hearing loss, Usher syndrome, BOR syndrome, delayed endolymphatic hydrops, acute onset hearing loss and Waardenburg syndrome, have been conducted by the Research Group of the Ministry of Health and Welfare for Intractable Diseases.

Genetic analysis of syndromic hearing loss

We performed genetic analysis of syndromic hearing loss including Branchio-oto-renal syndrome, Waardenburg syndrome, Osteogenesis imperfecta, Stickler syndrome, Spondyloepiphyseal dysplasia congenita, CHARGE syndrome, Jervell and Lange-Nielsen syndrome, Pendred syndrome, Klippel-Feil syndrome, Alport syndrome, Treacher-Collins syndrome, Perrault syndrome, and Norrie disease.

As a result, we identified genetic causes of syndromic hearing loss with different diagnostic yields in each syndrome (Ideura et al., Sci Rep 2019. Table 1). In addition, Waardenburg syndrome with a PAX3 gene mutation showed relatively mild hearing loss in comparison with that in patients with SOX10, MITF and EDNRB gene mutations (Ideura et al., Sci Rep 2019. Figure 1).

Table 1. Subjects and diagnostic ratio in this study.

Figure 1. The degree of hearing loss for all family members harboring causative variants. We calculated the hearing threshold in the worse hearing ear. Unilateral hearing loss: MITF 3 cases, EDNRB 1 case.

Epidemiological survey for acute onset hearing loss

In Japan, nationwide epidemiological surveys of various hearing disorders, including the idiopathic sudden sensorineural hearing loss, acute low-tone sensorineural hearing loss, perilymphatic fistula, mumps associated hearing loss, acoustic trauma, and acute noise-induced hearing loss have been conducted by the Research Group of the Ministry of Health and Welfare for Intractable Diseases from 2014 to 2016.

We summarized the results of this nationwide epidemiological survey in a series of 10 papers.

Wada T, Sano H, Nishio SY, Kitoh R, Ikezono T, Iwasaki S, Kaga K, Matsubara A, Matsunaga T, Murata T, Naito Y, Suzuki M, Takahashi H, Tono T, Yamashita H, Hara A, Usami SI. Differences between acoustic trauma and other types of acute noise-induced hearing loss in terms of treatment and hearing prognosis. Acta Otolaryngol. 2017;137(sup565):S48-S52.
Kitoh R, Nishio SY, Ogawa K, Kanzaki S, Hato N, Sone M, Fukuda S, Hara A, Ikezono T, Ishikawa K, Iwasaki S, Kaga K, Kakehata S, Matsubara A, Matsunaga T, Murata T, Naito Y, Nakagawa T, Nishizaki K, Noguchi Y, Sano H, Sato H, Suzuki M, Shojaku H, Takahashi H, Takeda H, Tono T, Yamashita H, Yamasoba T, Usami SI. Nationwide epidemiological survey of idiopathic sudden sensorineural hearing loss in Japan. Acta Otolaryngol. 2017;137(sup565):S8-S16.
Matsuda H, Sakamoto K, Matsumura T, Saito S, Shindo S, Fukushima K, Nishio SY, Kitoh R, Shibasaki O, Ito A, Araki R, Usami SI, Suzuki M, Ogawa K, Hasegawa T, Hagiwara Y, Kase Y, Ikezono T. A nationwide multicenter study of the Cochlin tomo-protein detection test: clinical characteristics of perilymphatic fistula cases. Acta Otolaryngol. 2017;137(sup565):S53-S59.
Yoshida T, Sone M, Kitoh R, Nishio SY, Ogawa K, Kanzaki S, Hato N, Fukuda S, Hara A, Ikezono T, Ishikawa K, Iwasaki S, Kaga K, Kakehata S, Matsubara A, Matsunaga T, Murata T, Naito Y, Nakagawa T, Nishizaki K, Noguchi Y, Sano H, Sato H, Suzuki M, Shojaku H, Takahashi H, Takeda H, Tono T, Yamashita H, Yamasoba T, Usami SI. Idiopathic sudden sensorineural hearing loss and acute low-tone sensorineural hearing loss: a comparison of the results of a nationwide epidemiological survey in Japan. Acta Otolaryngol. 2017;137(sup565):S38-S43.
Umesawa M, Kobashi G, Kitoh R, Nishio SY, Ogawa K, Hato N, Sone M, Fukuda S, Hara A, Ikezono T, Ishikawa K, Iwasaki S, Kaga K, Kakehata S, Matsubara A, Matsunaga T, Murata T, Naito Y, Nakagawa T, Nishizaki K, Noguchi Y, Sano H, Sato H, Suzuki M, Shojaku H, Takahashi H, Takeda H, Tono T, Yamashita H, Yamasoba T, Usami SI. Relationships among drinking and smoking habits, history of diseases, body mass index and idiopathic sudden sensorineural hearing loss in Japanese patients. Acta Otolaryngol. 2017;137(sup565):S17-S23.
Sato H, Kuwashima S, Nishio SY, Kitoh R, Fukuda S, Hara A, Hato N, Ikezono T, Ishikawa K, Iwasaki S, Kaga K, Matsubara A, Matsunaga T, Murata T, Naito Y, Nakagawa T, Nishizaki K, Noguchi Y, Ogawa K, Sano H, Sone M, Shojaku H, Takahashi H, Tono T, Yamashita H, Yamasoba T, Usami SI. Epidemiological survey of acute low-tone sensorineural hearing loss. Acta Otolaryngol. 2017;137(sup565):S34-S37.
Kitoh R, Nishio SY, Usami SI. Prognostic impact of gene polymorphisms in patients with idiopathic sudden sensorineural hearing loss. Acta Otolaryngol. 2017;137(sup565):S24-S29.
Usami SI, Kitoh R, Moteki H, Nishio SY, Kitano T, Kobayashi M, Shinagawa J, Yokota Y, Sugiyama K, Watanabe K. Etiology of single-sided deafness and asymmetrical hearing loss. Acta Otolaryngol. 2017;137(sup565):S2-S7.
Okada M, Hato N, Nishio SY, Kitoh R, Ogawa K, Kanzaki S, Sone M, Fukuda S, Hara A, Ikezono T, Ishikawa K, Iwasaki S, Kaga K, Kakehata S, Matsubara A, Matsunaga T, Murata T, Naito Y, Nakagawa T, Nishizaki K, Noguchi Y, Sano H, Sato H, Suzuki M, Shojaku H, Takahashi H, Takeda H, Tono T, Yamashita H, Yamasoba T, Usami SI. The effect of initial treatment on hearing prognosis in idiopathic sudden sensorineural hearing loss: a nationwide survey in Japan. Acta Otolaryngol. 2017;137(sup565):S30-S33.
Morita S, Fujiwara K, Fukuda A, Fukuda S, Nishio SY, Kitoh R, Hato N, Ikezono T, Ishikawa K, Kaga K, Matsubara A, Matsunaga T, Murata T, Naito Y, Nishizaki K, Ogawa K, Sano H, Sato H, Sone M, Suzuki M, Takahashi H, Tono T, Yamashita H, Yamasoba T, Usami SI. The clinical features and prognosis of mumps-associated hearing loss: a retrospective, multi-institutional investigation in Japan. Acta Otolaryngol. 2017;137(sup565):S44-S47.