Description: Uniparental disomy is a genetic condition in which both copies of a chromosome come from a single parent, rather than receiving one copy from each parent, as is typical. This anomaly can lead to genetic imbalance that affects the individual’s development and health. Uniparental disomy can be of two types: homozygous uniparental disomy, where both copies are identical, and heterozygous uniparental disomy, where the copies are different. This condition can arise from various mechanisms, such as nondisjunction during meiosis, where chromosomes do not separate properly, or from the fertilization of an egg by a sperm carrying an extra copy of a chromosome. Uniparental disomy is often associated with genetic syndromes, such as Prader-Willi syndrome and Angelman syndrome, which are caused by the lack of expression of specific genes on the affected chromosome. Identifying this condition is crucial in the field of medical genetics, as it can influence the diagnosis and management of various genetic diseases, as well as the understanding of inheritance and gene expression.
History: Uniparental disomy was first identified in 1980 when it was discovered that certain genetic syndromes were related to the inheritance of chromosomes from a single parent. Since then, numerous studies have expanded the understanding of this condition and its impact on human health.
Uses: Uniparental disomy is used in medical genetics to diagnose and understand genetic syndromes. It is also applied in inheritance studies and in research on diseases related to gene expression.
Examples: An example of uniparental disomy is Prader-Willi syndrome, which occurs when there is uniparental disomy of chromosome 15, resulting in the lack of expression of paternal genes. Another example is Angelman syndrome, which occurs due to the lack of expression of maternal genes on the same chromosome.
