Yes, SANDHIS is a Scrabble word!

Letter values in Scrabble US: S 1, A 1, N 1, D 2, H 4, I 1, S 1.

Is it a valid word?

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

the articulatory process whereby the pronunciation of a word or morpheme changes when it is followed immediately by another (especially in fluent speech)