NMNAT1 and pathologic nystagmus: In the patient 47–19 (Family 19): the 15-year-old boy with a reduction of visual acuity to the level of hand movements, hyperopic astigmatism, and mild nystagmus, panel-based NGS of LCA genes revealed a compound heterozygote of two variants in the NMNAT1: a novel substitution c.65A>G, p.(Asn22Ser) in exon 2 and a known variant in exon 5: c.769G>A.