Non-syndromic HL (NSHL) makes up 70% of all hereditary HL cases, with the majority of cases of pre-lingual HL arising from an autosomal recessive mutation in GJB2, located on chromosome 13.2 Gene GJB2 encodes the GJ protein Cx26, and its mutation has been linked to cochlear development disorders.3 Therefore, homozygous mutations, digenic heterozygous mutations, and knockout of GJB2 can cause congenital or late-onset NSHL.2 Moreover, the recent study by Liu et al. challenged the long-held belief that individuals with a single recessive heterozygous GJB2 mutation are resistant to HL. The gene discussed is GJB2; the disease is Down syndrome.