Yes, INFLECT is a Scrabble word!

Letter values in Scrabble US: I 1, N 1, F 4, L 1, E 1, C 3, T 1.

Is it a valid word?

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

change the form of a word in accordance as required by the grammatical rules of the language
vary the pitch of one's speech