SLC26A4 and sensorineural hearing loss disorder: Among 128 children with prelingual onset, nonsyndromic, sporadic or autosomal recessive, severe-to-profound SNHL, 22 (17.2 %) had two mutant alleles of GJB2 (DFNB1) and 23 (18.0 %) carried two mutant alleles of SLC26A4 (DFNB4).