MYO6 and MYO7a are two different genes for autosomal recessive deafness.

MYO7a is at locus DFNB2/ USH1B (Non-Syndromic/Syndromic)

MYO6 is at locus DFNB37.

Myosin7a and myosin6 are both genes which are expressed in hair cells, and are thus hair cell markers. If you want to detect hair cells in the cochlea, you can use either of them. There is essentially no difference. I recommend myosin7a for that purpose. Try the rabbit polyclonal anti-myosin7a from Proteus (Axxora), or the mouse monoclonal anti-myosin7a from the Developmental Studies Hybridoma Bank (DSHB). Both of them work perfectly in our hands.