Any change in the gene or a chromosome is caused by:

The correct answer is:

All of the above

• Any condition caused by a gene change is called a genetic condition (also called a genetic disorder). Some types of genetic conditions are caused by problems in one or more chromosomes. Chromosomes are the structures that hold genes. Each person has 23 pairs of chromosomes, or 46 in total.
• A mutation is a change in the DNA sequence of an organism. Mutations can result from errors in DNA replication during cell division, exposure to mutagens or a viral infection.
• Replication errors can also involve insertions or deletions of nucleotide bases that occur during a process called strand slippage.
• Genetic recombination refers to the rearrangement of DNA sequences by the breakage and rejoining of chromosomes or chromosomal segments.
• So answer is All the above