Answer:
Sometimes, gene variants (also known as mutations) prevent one or more proteins from working properly.
Explanation:
Germline mutations occur in gametes. Somatic mutations occur in other body cells.
Chromosomal alterations are mutations that change chromosome structure.
Point mutations change a single nucleotide.
Frameshift mutations are additions or deletions of nucleotides that cause a shift in the reading frame.
I hope this helps. :).