What is true of congenital musculoskeletal diseases?
are present at birth
develop after age 50
develop in late childhood
are caused by growing up in a polluted
environment

The correct answer is - present at birth.

Explanation:

Congenital musculoskeletal disease is a defect that occurs before birth in a baby or fetus during pregnancy where bone or muscles are affected or not grows properly.

It can be understood by the term as well as congenital means before birth and musculoskeletal means defect in bone or muscles. The example of such defects or diseases are cleft lip or palate, or joint contractures.

Thus, the correct answer is - present at birth.