Kromoszómaváltozások

Kromoszómaváltozások refers to alterations in the structure or number of chromosomes. Chromosomes are thread-like structures found in the nucleus of most living cells, carrying genetic information in the form of DNA. Changes in these structures can have significant implications for an organism's development and health.

There are two main categories of chromosomal abnormalities: numerical and structural. Numerical abnormalities occur when an individual has an abnormal number of chromosomes, either too many (trisomy) or too few (monosomy). For instance, Down syndrome is caused by trisomy 21, meaning individuals have an extra copy of chromosome 21. Structural abnormalities involve changes to the physical structure of a chromosome. These can include deletions, where a segment of a chromosome is lost; duplications, where a segment is repeated; inversions, where a segment is flipped; and translocations, where a segment of one chromosome breaks off and attaches to another.

These changes can arise spontaneously during the formation of sperm or egg cells, or they can occur after conception due to environmental factors or errors in DNA repair. While some chromosomal abnormalities are benign, many lead to developmental delays, intellectual disabilities, birth defects, and an increased risk of certain diseases, including cancer. Genetic testing and counseling are often used to detect and manage chromosomal variations.