Yes, ALLOGRAFTS is a Scrabble word!

Letter values in Scrabble US: A 1, L 1, L 1, O 1, G 2, R 1, A 1, F 4, T 1, S 1.

Is it a valid word?

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

tissue or organ transplanted from a donor of the same species but different genetic makeup; recipient's immune system must be suppressed to prevent rejection of the graft