Mozaikismus

Mozaikismus is a biological phenomenon where an individual possesses two or more genetically distinct cell lines that originate from a single zygote. This means that different parts of the body can have different sets of chromosomes or genes. The genetic differences can arise during early embryonic development, either through a mutation that occurs after fertilization or due to an error in chromosome segregation during cell division.

There are several types of mozaikismus. Sex chromosome mozaikismus, for example, can affect the development of sexual characteristics. Autosomal mozaikismus involves differences in non-sex chromosomes and can lead to a variety of phenotypic effects depending on which genes are affected and the proportion of cells with the altered genetic makeup. Mozaikismus can also occur at the chromosomal level, known as chromosomal mozaikismus, where some cells have a different number of chromosomes than others, such as in Down syndrome where some individuals may have a mixture of cells with 46 chromosomes and cells with 47 chromosomes (trisomy 21).

The extent and impact of mozaikismus vary greatly. Some individuals may have no noticeable symptoms, while others can experience a range of health issues, developmental delays, or physical abnormalities. The presence and significance of mozaikismus are often determined through genetic testing. Understanding mozaikismus is crucial in fields like genetics, developmental biology, and medicine, particularly in diagnosing and managing genetic disorders.