Ala40. There are four different substitutions at position 40Ala of Cx26, which can lead to non-syndromic recessive hearing loss (p.Ala40Glu and p.Ala40Gly), hearing loss with an uncertain mode of inheritance (p.Ala40Ser), or to KID syndrome (p.Ala40Val). Here, GJB2 is linked to KID syndrome.