Yes, ALLELES is a Scrabble word!

Letter values in Scrabble US: A 1, L 1, L 1, E 1, L 1, E 1, S 1.

Is it a valid word?

ALLELES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

(genetics) either of a pair (or series) of alternative forms of a gene that can occupy the same locus on a particular chromosome and that control the same character