Microdeletion syndrome explained

A microdeletion syndrome is a syndrome caused by a chromosomal deletion smaller than 5 million base pairs (5 Mb) spanning several genes that is too small to be detected by conventional cytogenetic methods or high resolution karyotyping (2–5 Mb).^{[1] [2]} Detection is done by fluorescence in situ hybridization (FISH). Larger chromosomal deletion syndromes are detectable using karyotyping techniques.

Examples

• DiGeorge syndrome or velocardiofacial syndrome^[3] – most common microdeletion syndrome
• Prader–Willi syndrome^{[4] [5]}
• Angelman syndrome^[4]
• Neurofibromatosis type I^[6]
• Neurofibromatosis type II^{[7] [8]}
• Williams syndrome^[9]
• Miller–Dieker syndrome^[10]
• Smith–Magenis syndrome^[11]
• Rubinstein–Taybi syndrome^[12]
• Wolf–Hirschhorn syndrome^[13]

Further reading

• Book: H. William Taeusch. Roberta A. Ballard. Christine A. Gleason. Mary Ellen Avery. Avery's Diseases of the Newborn. 2005. Elsevier Health Sciences. 0-7216-9347-4. 210–215.
• Microdeletions and Molecular Genetics
• Microdeletion syndromes (chromosomes 1 to 11) on UpToDate
• List of 100 microdeletion/duplication syndromes detected by array-CGH on GENOMA
• Book: Molecular Cytogenetics : Protocols and Applications. Schwartz, Stuart. Graf, Michael D.. Ch 19. Microdeletion Syndromes: Characteristics and Diagnosis. Methods in Molecular Biology. 204. Sep 13, 2002. 275–290. 10.1385/1-59259-300-3:275. 12397804.
• Book: Vissers, LE. Stankiewicz, P. Genomic Structural Variants . Microdeletion and Microduplication Syndromes . Methods in Molecular Biology. 2012. 838. 29–75. 10.1007/978-1-61779-507-7_2. 22228006. 978-1-61779-506-0.
• Book: Slavotinek, Anne. Microdeletion Syndromes. 10.1002/9780470015902.a0005549.pub2. eLS. 2012. 978-0470016176.
• 13 chromosomal disorders you may not have heard of

Notes and References

1. Book: H. William Taeusch. Roberta A. Ballard. Christine A. Gleason. Mary Ellen Avery. Avery's Diseases of the Newborn. 2005. Elsevier Health Sciences. 0-7216-9347-4. 210–215.
2. Web site: Microdeletion syndrome. Genetics Home Reference. 19 April 2014. 17 April 2014.
3. Shaikh. TH. Kurahashi. H. Saitta. SC. O'Hare. AM. Hu. P. Roe. BA. Driscoll. DA. McDonald-McGinn. DM. Zackai. EH. Budarf. ML. Emanuel. BS. Chromosome 22-specific low copy repeats and the 22q11.2 deletion syndrome: genomic organization and deletion endpoint analysis.. Human Molecular Genetics. 1 March 2000. 9. 4. 489–501. 10.1093/hmg/9.4.489. 10699172. free.
4. Buiting. K. Saitoh. S. Gross. S. Dittrich. B. Schwartz. S. Nicholls. RD. Horsthemke. B. Inherited microdeletions in the Angelman and Prader-Willi syndromes define an imprinting centre on human chromosome 15.. Nature Genetics. April 1995. 9. 4. 395–400. 7795645. 10.1038/ng0495-395. 7184110.
5. Runte. M. Varon. R. Horn. D. Horsthemke. B. Buiting. K. Exclusion of the C/D box snoRNA gene cluster HBII-52 from a major role in Prader-Willi syndrome.. Human Genetics. February 2005. 116. 3. 228–30. 10.1007/s00439-004-1219-2. 15565282. 23190709.
6. Pasmant. E. Sabbagh. A. Spurlock. G. Laurendeau. I. Grillo. E. Hamel. MJ. Martin. L. Barbarot. S. Leheup. B. Rodriguez. D. Lacombe. D. Dollfus. H. Pasquier. L. Isidor. B. Ferkal. S. Soulier. J. Sanson. M. Dieux-Coeslier. A. Bièche. I. Parfait. B. Vidaud. M. Wolkenstein. P. Upadhyaya. M. Vidaud. D. members of the NF France. Network. NF1 microdeletions in neurofibromatosis type 1: from genotype to phenotype.. Human Mutation. June 2010. 31. 6. E1506-18. 20513137. 10.1002/humu.21271. 24525378. free.
7. Rouleau. GA. Merel. P. Lutchman. M. Sanson. M. Zucman. J. Marineau. C. Hoang-Xuan. K. Demczuk. S. Desmaze. C. Plougastel. B. Alteration in a new gene encoding a putative membrane-organizing protein causes neuro-fibromatosis type 2.. Nature. 10 June 1993. 363. 6429. 515–21. 10.1038/363515a0. 8379998. 1993Natur.363..515R. 24532924.
8. Beck. Megan. Peterson. Jess F.. McConnell. Juliann. McGuire. Marianne. Asato. Miya. Losee. Joseph E.. Surti. Urvashi. Madan-Khetarpal. Suneeta. Rajkovic. Aleksandar. Yatsenko. Svetlana A.. Craniofacial abnormalities and developmental delay in two families with overlapping 22q12.1 microdeletions involving the gene. American Journal of Medical Genetics Part A. May 2015. 167. 5. 1047–1053. 10.1002/ajmg.a.36839. 25810350. 205319722.
9. Tassabehji. M. Metcalfe. K. Karmiloff-Smith. A. Carette. MJ. Grant. J. Dennis. N. Reardon. W. Splitt. M. Read. AP. Donnai. D. Williams syndrome: use of chromosomal microdeletions as a tool to dissect cognitive and physical phenotypes.. American Journal of Human Genetics. January 1999. 64. 1. 118–25. 10.1086/302214. 9915950. 1377709.
10. Huang. HC. Bautista. SL. Chen. BS. Chang. KP. Chen. YJ. Wuu. SW. Miller-Dieker syndrome with microdeletion of chromosome 17p13.3: report of one case.. Zhonghua Minguo Xiao Er Ke Yi Xue Hui Za Zhi [Journal]. Zhonghua Minguo Xiao Er Ke Yi Xue Hui. 1996. 38. 6. 472–6. 9473821.
11. Bi. W. Yan. J. Stankiewicz. P. Park. SS. Walz. K. Boerkoel. CF. Potocki. L. Shaffer. LG. Devriendt. K. Nowaczyk. MJ. Inoue. K. Lupski. JR. Genes in a refined Smith-Magenis syndrome critical deletion interval on chromosome 17p11.2 and the syntenic region of the mouse.. Genome Research. May 2002. 12. 5. 713–28. 10.1101/gr.73702. 11997338. 186594.
12. Wójcik. C. Volz. K. Ranola. M. Kitch. K. Karim. T. O'Neil. J. Smith. J. Torres-Martinez. W. Rubinstein-Taybi syndrome associated with Chiari type I malformation caused by a large 16p13.3 microdeletion: a contiguous gene syndrome?. American Journal of Medical Genetics Part A. February 2010. 152A. 2. 479–83. 20101707. 10.1002/ajmg.a.33303. 205312346.
13. Rauch. A. Schellmoser. S. Kraus. C. Dörr. HG. Trautmann. U. Altherr. MR. Pfeiffer. RA. Reis. A. First known microdeletion within the Wolf-Hirschhorn syndrome critical region refines genotype-phenotype correlation.. American Journal of Medical Genetics. 1 April 2001. 99. 4. 338–42. 11252005. 10.1002/ajmg.1203.