RP9 and retinitis pigmentosa: Notably, ophthalmologic evaluation of the proband and his parents did not detect evidence of retinitis pigmentosa to date, suggesting that RP9 variants may present with later onset, have incomplete penetrance, or that the RP9 missense mutations (c.410A > T; p.His137Leu and c.509A > G; p.Asp170Gly) previously reported in a single family may actually be benign rare variants.10 Of these two reported variants, only c.509A > G (rs104894039) was observed in the Genome Aggregation Database (gnomAD; http://gnomad.broadinstitute.org/), but with a very rare minor allele frequency (0.000065).