This case also highlights the diagnostic significance of next-generation sequencing (NGS), which identified a novel pathogenic missense variant in the <i>NF1</i> gene (c.988G>C; p.Ala330Pro).<h4>Case presentation</h4>A 16-year-old female presented with a 5-year history of progressive, painless right upper eyelid swelling and ptosis. The gene discussed is NF1; the disease is ptosis.