Rethink Genetics A recount of human genes ups the number to at least 46,831 The new estimate is based on a broader definition of just what a gene is COUNTING ON IT The number of human genes depends on how scientists define a gene. Svisio/iStockphoto By Tina Hesman Saey September 17, 2018 at 7:00 am - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Share on Facebook (Opens in new window) Facebook Share on Reddit (Opens in new window) Reddit Share on X (Opens in new window) X Print (Opens in new window) Print Figuring out how many genes are in the human genetic instruction manual, or genome, isn’t as easy as scientists once thought.