USH2A and Abnormal retinal morphology: Another study also assessed syndromic and nonsyndromic USH2A patients but found no difference in retinal disease progression when comparing patients with the p.(Cys759Phe) amino acid substitution in USH2A, which is associated with NSRP, to patients with a p.(Glu767Serfs*21) frameshift in USH2A, which is implicated in Usher syndrome6.