Yes, INHERITANCES is a Scrabble word!

Letter values in Scrabble US: I 1, N 1, H 4, E 1, R 1, I 1, T 1, A 1, N 1, C 3, E 1, S 1.

Is it a valid word?

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

hereditary succession to a title or an office or property
that which is inherited; a title or property or estate that passes by law to the heir on the death of the owner
(genetics) attributes acquired via biological heredity from the parents
any attribute or immaterial possession that is inherited from ancestors

Also: hereditary pattern.