What are Chromosomal Mutations?
- Chromosomal mutations, also known as chromosome aberrations, refer to any changes in the normal number or structure of chromosomes.
- These mutations can affect large segments of DNA and are often visible during the metaphase stage of cell division.
Types of Chromosomal Mutations
There are two major categories:
A. Numerical Disorders
- Involve changes in the number of chromosomes.
- Can lead to conditions such as Down syndrome or Turner syndrome.
B. Structural Aberrations
- Involve alterations in the physical structure of chromosomes.
- Can include deletions, duplications, inversions, or translocations.
Inheritance of Chromosomal Aberrations
- If the mutation occurs in reproductive cells (egg or sperm), the child will inherit the anomaly, and it will be present in every cell of the body.
- Mutations that happen after fertilization result in mosaicism, where only some cells carry the mutation.
- Chromosomal aberrations can be inherited from parents or may arise spontaneously (known as de novo mutations).
- Parental chromosome analysis is often performed when a child has a chromosomal anomaly to determine if it is inherited or a new mutation.