PCDH15 and Usher syndrome type 1F: Deeply investigated for its role in the maintenance of the normal retinal and cochlear function and for its involvement in causing hearing loss and Usher Syndrome Type IF (USH1F) in the presence of mutations in PCDH15 gene [126], PCDH15 has recently gained attention for its potential implication also in neurodevelopmental disorders (Table 2).