parentage vs line of descent

parentage and line of descent both are nouns.

Word	Noun	Adjective	Verb	Adverb
parentage	Yes	No	No	No
line of descent	Yes	No	No	No

As nouns, parentage and line of descent are synonyms defined as:

parentage and line of descent: the hereditary derivation of an individual

Other synonyms of parentage include ancestry, blood, blood line, bloodline, descent, line, lineage, origin, pedigree, stemma, stock.

parentage (noun)	line of descent (noun)
the hereditary derivation of an individual	the hereditary derivation of an individual
the kinship relation of an offspring to the parents	the kinship relation between an individual and the individual's progenitors
the state of being a parent