what became of my second brother I never knew any more than father or mother did know what becam

what became of my second brother I never knew any more than father or mother did know what becam

What became of my second brother I never knew, any more than my father or mother knew what became of me.

become of = happen to
I never knew any more than =I knew as little as my father or mother knew ...
全句意思是，我不知道我的第二个弟弟身上发生了什么事，就像我的父亲或母亲不知道我身上发生了什么一样。

至于二哥的下落，我至今一无所知，就像我父母对我后来的境况也全然不知一样。