A genomic mutation is defined as a change in the number of chromosomes in an organism or cell. They are heritable. Genomic mutations are grouped with chromosomal mutations, in which the structure of chromosomes visible under the light microscope changes, to form chromosomal aberrations.
Chromosomal mutations are structural chromosomal aberrations.
Genome mutations are numerical chromosome aberrations .
Mutations that affect only one gene and are therefore not visible under the light microscope are called gene mutations.