Editing Comparative genomic hybridization (section)

====Submicroscopic aberrations====
[[Prader–Willi syndrome]] (PWS) is a paternal structural abnormality involving 15q11-13, while a maternal aberration in the same region causes Angelman syndrome (AS). In both syndromes, the majority of cases (75%) are the result of a 3–5 Mb deletion of the PWS/AS critical region.<ref>L'Hermine AC, Aboura A, Brisset S, Cuisset L, Castaigne V, Labrune P, Frydman R, Tachdjian G. (2003) Fetal phenotype of Prader–Willi syndrome due to maternal disomy for chromosome 15. Prenat Diagn 23:938–943.</ref> These small aberrations cannot be detected using [[cytogenetics]] or conventional CGH, but can be readily detected using array CGH. As a proof of principle Vissers et al. (2003) constructed a genome wide array with a 1 Mb resolution to screen three patients with known, FISH-confirmed microdeletion syndromes, including one with PWS. In all three cases, the abnormalities, ranging from 1.5 to 2.9Mb, were readily identified.<ref>{{cite journal | vauthors = Vissers LE, de Vries BB, Osoegawa K, Janssen IM, Feuth T, Choy CO, Straatman H, van der Vliet W, Huys EH, van Rijk A, Smeets D, van Ravenswaaij-Arts CM, Knoers NV, van der Burgt I, de Jong PJ, Brunner HG, Geurts , van Kessel A, Schoenmakers EF, Veltman JA | year = 2003 | title = Array-based comparative genomic hybridization for the genome-wide detection of submicroscopic chromosomal abnormalities | journal = Am J Hum Genet | volume = 73 | issue = 6| pages = 1261–1270 | doi = 10.1086/379977 | pmid = 14628292 | pmc = 1180392 }}</ref> Thus, array CGH was demonstrated to be a specific and sensitive approach in detecting submicroscopic aberrations.

When using overlapping microarrays, it is also possible to uncover breakpoints involved in chromosomal aberrations.