Yes, LINEAGE is a Scrabble word!

Letter values in Scrabble US: L 1, I 1, N 1, E 1, A 1, G 2, E 1.

Is it a valid word?

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

the descendants of one individual
the kinship relation between an individual and the individual's progenitors
the number of lines in a piece of printed material
a rate of payment for written material that is measured according to the number of lines submitted
inherited properties shared with others of your bloodline

Also: line of descent, blood line.