We are two brothers,i am the first son..My dad died when i was 10 years old,we grew up with the help of my mom..Now i am 25 years old,my immediate brother is 20 years old currently;which he is 5 years old when our dad died,we grew up as brothers doing things together went to the same school,infact anything you think of brothers can do,we did it together...Our mother is late now,she died a year ago after some months later,my brother brought this issue of first son...Now he is saying i am not the biological brother of him,our parents married without no child so they adopted me after 5 years our mom concevied and gave birth to him...So he is the biological son of our parents thats made him the first son...I asked him were he got the informations from cuz our parents had died...He said neighbours told him who witnessed what happened then and a written document by our dad but our dad doesnt change my position as first son in the document but my brother insist am not first son and have no right over our properties