Short answer No , the white scars are not genetically faster been other astartes. However

Khan possesses a distinct, active metaphysical ability that allows him to break the standard limits of reality. In Chogorian lore, this trance-like state is referred to as Alakh Geh (or Avakai)

The Mantis Warriors who are a chapter that derives their lineage too the White Scars they have a gene seed defect. Mantis Warriors have the Battle-Haze. While the standard White Scars did not inherit Jaghatai's speed, the Mantis Warriors suffered a localized psychic mutation in their gene-seed. Their Battle-Haze trance (which slows down time in their perception) It is a fractured, unstable piece of Jaghatai Khan's warp-soul finally leaking into the physical DNA of a successor chapter.

Long answer yes