SOLVED. Redhead Kid thinks he's adopted. [s]

[Jennifer]

I read it while i was in elementary school around 10 years ago ish probably a 90s book though, where a red head kid was the only red head in his family he always questioned if he was adopted and there was this king who was looking for his long lost son and was blood testing red head children and this kid came out to have the blood type of the kid but got scared of the fact that he was going to lose his family that raised him so he went home and never spoke about it to his family.

[Zev]

This sounds like "Marvin Redpost: Kidnapped at Birth?"by Louis Sachar.

[Rainbowheart]

Marvin Redpost: Kidnapped at Birth? for the link.

[Jennifer]

Yes, Thank you!