This patient's ophthalmic findings were consistent with HGSNAT‐associated RP, however, HGSNAT activity was well within the normal range (2.1 nmol/hr/mg protein), so while no pathogenic variants were identified using the 236‐gene RETINAL panel of a clinical exome not including HGSNAT, it was not necessary to proceed to HGSNAT gene sequencing. The gene discussed is HGSNAT; the disease is retinitis pigmentosa 1.