P4HA2 and hearing loss disorder: The P4HA2 p.R439Q variant has also been reported in the deaf family described by Ben Said et al. (2016) but was excluded as the cause of hearing loss because it is classified as benign or tolerated by several predictors (such as SIFT and Polyphen-2) and affects a residue that is not conserved in the mouse P4ha2 ortholog (NP_035161).