HSD17B4 and Usher syndrome type 2A: Indeed, the variant found in USH2A (MIM:276901) is associated with Usher syndrome type IIA and was defined as benign; HSD17B4 (MIM:601860) is associated with Perrault syndrome (MIM:233400) that has a clinical presentation not found in the patients; while MYO1A has been excluded as a HI-associated gene (28).