Kevin Portis, age 9, of Thomasville, N.C., for his question:

WHAT CAUSES A PERSON TO BE A HUNCHBACK?

Hunchback is a severe rounded or sharp prominence of the upper part of the back.

Because part of the back sticks out like a big hump, the condition is sometimes called humpback.

Hunchback is caused by any condition that deforms the bones of the upper part of the spine. The most common cause is tuberculosis of the spine, or Pott's disease.

Hunchback involves the portion of the spine to which the ribs are connected. The hump results when the front part of the spinal bones collapses, spreading the back part.