Mandy Sellars (born 20 February 1975 in Lancashire, United Kingdom) is a British woman with a rare genetic mutation that has resulted in extraordinary growth in both of her legs.
In 2006, some doctors diagnosed Sellars as having Proteus syndrome, a very rare condition thought to affect only 120 people worldwide, but more recent diagnoses have focused on a PIK3CA gene mutation.
Some reports still describe her condition as a rare form of Proteus syndrome, but Sellars herself has disputed the diagnosis.Sellars's condition has been covered in several television programs, leading Sellars to jokingly describe herself as a "part-time TV star".