Aneuploidiát

Aneuploidiát is a chromosomal abnormality characterized by an abnormal number of chromosomes, meaning the cell has extra or missing chromosomes. This deviation from the normal diploid set of chromosomes is a significant departure from the typical genetic makeup. In humans, the normal somatic cell contains 46 chromosomes arranged in 23 pairs. Aneuploidiát occurs when this number is not a multiple of the haploid number, which is 23 in humans. For instance, having 47 chromosomes or 45 chromosomes would be considered aneuploidiát.

This condition can arise during cell division, specifically during meiosis or mitosis, when chromosomes fail to separate properly. This error, known as nondisjunction, can lead to gametes (sperm or egg cells) with an incorrect number of chromosomes. Fertilization with such a gamete results in an embryo with aneuploidiát. The consequences of aneuploidiát vary widely depending on the specific chromosomes involved and the extent of the abnormality. Some forms of aneuploidiát are lethal and result in miscarriage, while others can lead to developmental disorders and syndromes.

Common examples of aneuploidiát in humans include Down syndrome (trisomy 21), where an individual has three copies of chromosome 21, and Turner syndrome (monosomy X), where a female has only one X chromosome. Many forms of cancer are also associated with aneuploidiát, as cells accumulate chromosomal abnormalities during tumor progression. The study of aneuploidiát is crucial for understanding genetic disorders, developmental biology, and the mechanisms underlying cancer.