TMTC4 and Progressive sensorineural hearing impairment: Two affected individuals in a Korean family — each with history of progressive sensorineural hearing loss (SNHL) over their lives, albeit to different degrees — were found on whole-exome sequencing to be compound heterozygous for 2 candidate pathogenic missense variants in TMTC4 (c.547 G>A: p.Glu183Lys [p.E183K; Combined Annotation Dependent Depletion (CADD) phred 27.00] and c.575 C>T: p.Ala192Val [p.A192V; CADD phred 31.00]), while the parents and the unaffected sibling each only carried one of these variants (Figure 5).