Trisomy 16
Trisomy 16 is an unusual thing within a person where there are three copies of chromosome 16 rather than two. It often leads to women losing their baby in miscarriage. It is the second most common cause of miscarriage due to chromosomes (closely following X-chromosome monosomy).[1] About 6% of miscarriages have trisomy 16.[2] Those mostly occur in pregnancy from 8 to 15 weeks after the last menstrual period.[2]
There are four types of Trisomy 16, "full trisomy 16", "translocation trisomy 16", "mosaic trisomy 16", and "partial trisomy 16":
- Full trisomy 16 or free trisomy 16 - all body cells have an extra copy of chromosome 16
- Translocation trisomy 16 - all body cells have an extra copy of the chromosome 16, but it moved close to another chromosome. In genetics, this movement is called translocation
- Mosaic trisomy 16 - Some body cells have three copies of chromosome 16, others have the usual two copies. In genetics, when there are different karyotypes, this is called a mosaic.
- Partial trisomy 16 - The body cells have two copies of chromosome 16, but part of the chromosome is copied. This makes chromosome 16 a little longer. For the part that is copied there are three copies of the information.
It is not possible for a child to be born alive with an extra copy of this chromosome present in all cells (full trisomy 16 or translocation trisomy 16).[3] It is possible, however, for a child to be born alive with the mosaic form.[4][5] Normally humans have two copies of chromosome 16, one inherited by each parent. This chromosome represents almost 3% of all DNA in cells.[6]
References
change- ↑ DeCherney, Alan H.; Nathan, Lauren; Goodwin, T. Murphy; Laufer, Neri, eds. (2007). Current diagnosis & treatment: Obstetrics & gynecology (10th ed.). New York: McGraw-Hill. ISBN 978-0-07-143900-8.
- ↑ 2.0 2.1 Benn, Peter (1998-09-01). "Trisomy 16 and trisomy 16 mosaicism: A review". American Journal of Medical Genetics. 79 (2): 121–133. doi:10.1002/(SICI)1096-8628(19980901)79:2<121::AID-AJMG8>3.0.CO;2-T. ISSN 1096-8628. PMID 9741470.
- ↑ Seller, MJ; Fear, C; Kumar, A; Mohammed, S (2004). "Trisomy 16 in a mid-trimester IVF foetus with multiple abnormalities". Clinical Dysmorphology. 13 (3): 187–190. doi:10.1097/01.mcd.0000133498.91871.1b. ISSN 0962-8827. OCLC 196772467. PMID 15194958. BL Shelfmark 3286.273700.
- ↑ Simensen, RJ; Colby, RS; Corning, KJ (2003). "A prenatal counseling conundrum: mosaic trisomy 16. A case study presenting cognitive functioning and adaptive behavior". Genetic Counselling. 14 (3): 331–6. ISSN 1015-8146. OCLC 210520912. PMID 14577678. BL Shelfmark 4111.845000.
- ↑ Langlois S, Yong PJ, Yong SL; Yong, P J; Yong, S L; Barrett, I; Kalousek, D K; Miny, P; Exeler, R; Morris, K; Robinson, W P; et al. (2006). "Postnatal follow-up of prenatally diagnosed trisomy 16 mosaicism". Prenatal Diagnosis. 26 (6): 548–558. doi:10.1002/pd.1457. OCLC 108807898. PMID 16683298. BL Shelfmark 6607.646000.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ↑ Yong, PJ; Barrett, IJ; Kalousek, DK; Robinson, WP (2003). "Clinical aspects, prenatal diagnosis, and pathogenesis of trisomy 16 mosaicism". Journal of Medical Genetics. 40 (3): 175–82. doi:10.1136/jmg.40.3.175. PMC 1735382. PMID 12624135.