What are the types of chromosomal mutations?

There are two main types of chromosomal mutations – structural mutations and number mutations. 

Structural mutations, also known as chromosomal mutations I, are caused when chromosomes undergo contortions, form pairings, or break and form sticky ends, all of which result in alterations in the chromosomal structure. These alterations change the genes on the chromosome, which affects protein production. Structural chromosomal mutations can be harmful to an individual, often resulting in developmental difficulties and even death. 

Number mutations, also known as chromosomal mutations II, result from changes in the number of chromosomes present in the cell. These may occur due to a chromosome breakage or due to failure of homologous chromosomes to separate properly during cell division. Number chromosomal mutations may produce individuals with missing chromosomes or extra chromosomes, leading to conditions such as Down syndrome or Klinefelter syndrome.