Kromosoomihäired

Kromosoomihäired, also known as chromosomal abnormalities, are changes in the number or structure of chromosomes within a cell. Chromosomes are thread-like structures found in the nucleus of most living cells, carrying genetic information in the form of genes. These abnormalities can occur during the formation of egg or sperm cells, or shortly after fertilization. They can affect any chromosome, including sex chromosomes (X and Y) and autosomes.

There are two main categories of chromosomal abnormalities: numerical and structural. Numerical abnormalities involve an extra or missing chromosome. A common example is Down syndrome (Trisomy 21), where individuals have three copies of chromosome 21 instead of the usual two. Klinefelter syndrome, affecting males, involves an extra X chromosome (XXY). Structural abnormalities involve a change in the physical structure of a chromosome, such as deletions (a piece of a chromosome is missing), duplications (a piece of a chromosome is repeated), translocations (a piece of one chromosome breaks off and attaches to another), and inversions (a piece of a chromosome is flipped).

The effects of chromosomal abnormalities vary widely depending on the specific change and which chromosomes are involved. Some abnormalities can lead to developmental delays, intellectual disabilities, physical birth defects, and an increased risk of certain health conditions. Others may have no apparent effect or may result in miscarriage. Diagnosis often involves genetic testing, such as karyotyping, which examines the number and appearance of chromosomes. While many chromosomal abnormalities cannot be cured, genetic counseling can provide information and support for individuals and families affected by these conditions.