Uniparental disomy
| Uniparental disomy | |
|---|---|
| Animation of uniparental isodisomy | |
| Specialty | Medical genetics |
Uniparental disomy (UPD) occurs when a person receives two copies of a
UPD has been found to occur in about 1 in 2,000 births.[4]
Pathophysiology
UPD can occur as a random event during the formation of egg cells or sperm cells or may happen in early fetal development. It can also occur during trisomic rescue.
- When the child receives two (different)
- When the child receives two (identical) replica copies of a single homologue of a chromosomal duplication.
- A meiosis I error can result in isodisomic UPD if the gene loci in question crossed over, for example, a distal isodisomy would be due to duplicated gene loci from the maternal grandmother that crossed over and due to an error during meiosis I, ended up in the same gamete.[5]
- A meiosis II error can result in heterodisomy UPD if the gene loci crossed over in a similar fashion.[5]
Phenotype
Most occurrences of UPD result in no
Uniparental
- The most well-known conditions include Prader–Willi syndrome and Angelman syndrome. Both of these disorders can be caused by UPD or other errors in imprinting involving genes on the long arm of chromosome 15.[6]
- Other conditions, such as Beckwith–Wiedemann syndrome, are associated with abnormalities of imprinted genes on the short arm of chromosome 11.
- Chromosome 14 is also known to cause particular symptoms such as skeletal abnormalities, intellectual disability, and joint contractures, among others.[7][8]
UPD has rarely been studied prospectively, with most reports focusing on either known conditions or incidental findings. It has been proposed that the incidence may not be as low as believed, rather it may be under-reported.[9]
All chromosomes
Genome wide UPD, also called uniparental diploidy, is when all chromosomes are inherited from one parent. Only in mosaic form can this phenomenon be compatible with life. As of 2017, there have only been 18 reported cases of genome wide UPD.[10]
History
The first clinical case of UPD was reported in 1988 and involved a girl with cystic fibrosis and short stature who carried two copies of maternal chromosome 7.[11] Since 1991, out of the 47 possible disomies, 29 have been identified among individuals ascertained for medical reasons. This includes chromosomes 2, 5–11, 13–16, 21 and 22.
See also
References
- S2CID 19446912.
- ISBN 0-8153-4183-0.
- PMID 24356988.
- PMID 31607426.
- ^ a b c d "Meiosis: Uniparental Disomy". Retrieved 29 February 2016.
- ^ Angelman Syndrome, Online Mendelian Inheritance in Man
- ^ "OMIM Entry - # 608149 - KAGAMI-OGATA SYNDROME". omim.org. Retrieved 1 September 2020.
- ^ Duncan, Malcolm (1 September 2020). "Chromosome 14 uniparental disomy syndrome information Diseases Database". www.diseasesdatabase.com. Retrieved 1 September 2020.
- PMID 24339543. Archived from the original on 2014-02-20.)
{{cite journal}}: CS1 maint: unfit URL (link - PMID 29046733.
- PMID 2893543.
External links
- "Uniparental disomy". Department of Medical Genetics, University of British Columbia. Archived from the original on 2002-06-17.
{{cite web}}: CS1 maint: unfit URL (link) - T. Liehr: Cases with uniparental disomy
- UPD Animations: UPD Animations
This article incorporates public domain text from The U.S. National Library of Medicine