What is the Difference Between Mosaicism and Uniparental Disomy?

Mosaicism and uniparental disomy (UPD) are two genetic anomalies that arise from errors in meiosis and/or mitosis. They can occur independently or in combination, and chromosomal mosaicism can be associated with uniparental disomy. The key differences between mosaicism and uniparental disomy are:

1. Presence of different genetic makeup: Mosaicism is the presence of two or more different chromosome complements within the same individual, meaning cells within the same person have a different genetic makeup. In contrast, uniparental disomy is the condition where an individual has two copies of a chromosome from only one parent, either through isodisomy (both chromosomes are identical copies) or heterodisomy (the two chromosomes are not identical).
2. Origin: Mosaicism can be either germline mosaicism, which occurs in germ cells (reproductive cells) and can be transmitted to offspring, or somatic mosaicism, which occurs in non-reproductive cells and is not transmitted to offspring. Uniparental disomy, on the other hand, results from meiotic or mitotic errors.
3. Associated diseases: Mosaicism is associated with conditions such as Klinefelter syndrome and Turner syndrome. Uniparental disomy is associated with Prader-Willi syndrome and Angelman Syndrome.

In summary, mosaicism is characterized by the presence of different chromosomal complements within the same individual, while uniparental disomy involves having two copies of a chromosome from only one parent. Both conditions arise from errors in cell division but are associated with different diseases and genetic makeups.

Comparative Table: Mosaicism vs Uniparental Disomy

Mosaicism and uniparental disomy are two genetic anomalies that arise from errors in meiosis and/or mitosis. They can occur independently or in combination. Here is a table comparing the differences between mosaicism and uniparental disomy:

Mosaicism is a condition in which cells within the same person have a different genetic makeup, while uniparental disomy is a state where an individual inherited two copies of a chromosome from the same parent.