<b>Case summary:</b> We report the case of a 9-year-old girl identified through population genetic screening as a homozygous carrier of the <i>NPPA</i> c.449G>A (p.Arg150Gln) variant who subsequently developed symptomatic paroxysmal atrial fibrillation (AF) at the age of 18. This evidence concerns the gene NPPA and Paroxysmal atrial fibrillation.