Who is Nhamo from Nervous Conditions and what is their importance?

Nhamo is Tambu's brother. Nhamo attends school at a mission some twenty miles from his home. The plan was for Nhamo to attend school, distinguish himself academically and enter a good profession. With the money he will earn, the family will be lifted from the squalor in which they live. He dies in 1968, when Tambu is thirteen years old.