[@Hillan]
It is mentioned by the creator himself when asked, and so yes it is cannon. The rest of his race is normal power levels, but does come with race based boosts such as surviving in space, tails etc. 

"It was said by Akira Toriyama that Frieza was a "hybrid mutant" of his race (due to an accidental mutation a long time ago), and a hybrid refers to an entity that is born from two parents of separate species or variety."