lisäkromosomien

Lisäkromosomien refers to the presence of extra chromosomes in a cell or organism. This condition, known as aneuploidy, can arise from errors during cell division, specifically in meiosis when gametes (sperm and egg cells) are formed, or in mitosis when somatic cells divide. The extra chromosome can be a full copy of a chromosome or a partial segment of one.

The consequences of having extra chromosomes vary greatly depending on which chromosome is affected and the extent of the duplication. In humans, trisomy, where there are three copies of a particular chromosome instead of the usual two, is a well-known cause of genetic disorders. For example, Trisomy 21 leads to Down syndrome, Trisomy 18 results in Edwards syndrome, and Trisomy 13 causes Patau syndrome. These conditions are often associated with developmental delays, intellectual disability, and characteristic physical features. Monosomy, the absence of one chromosome from a pair, can also occur, though it is often more severe.

While some forms of aneuploidy are compatible with life and lead to specific syndromes, others are usually lethal early in development. The presence of extra genetic material can disrupt the delicate balance of gene expression and protein production, leading to a cascade of developmental abnormalities. Research continues to explore the mechanisms behind aneuploidy and its varied impacts on health and development.