IGHG3 and hearing loss disorder: A 61 year-old woman with subnormal levels of IgG1 and IgG3 reported having “steroid-responsive hearing loss.” A 45 year-old man with subnormal levels of IgG1 and IgG3 was reported to have “idiopathic hearing loss responding to prednisone within three months.” Considering these patients to have probable ASNHL, our estimated prevalence of ASNHL in 406 patients with IgGSD during a mean follow-up interval of 8 ± 4 y was 0.74% [95% CI: 0.19, 2.33].