Editing Comparative genomic hybridization (section)

===Conventional===

Conventional CGH has been used mainly for the identification of chromosomal regions that are recurrently lost or gained in tumors, as well as for the diagnosis and prognosis of cancer.<ref>Weiss MM, Kuipers EJ, Meuwissen SG, van Diest PJ, Meijer GA (2003) Comparative genomic hybridization as a supportive tool in diagnostic pathology. J Clin Pathol 56:522–527.</ref> This approach can also be used to study [[chromosomal aberrations]] in [[fetal]] and [[neonatal]] genomes. Furthermore, conventional CGH can be used in detecting chromosomal abnormalities and have been shown to be efficient in diagnosing complex abnormalities associated with human genetic disorders.<ref name="Oostlander,Meijer,Ylstra" />

====In cancer research====
CGH data from several studies of the same tumor type show consistent patterns of non-random genetic aberrations.<ref name="Forozan,Karhu,Kononen,Kallioniemi,Kallioniemi">{{cite journal | vauthors = Forozan F, Karhu R, Kononen J, Kallioniemi A, Kallioniemi OP | year = 1997 | title = Genome screening by comparative genomic hybridization | journal = Trends Genet | volume = 13 | issue = 10| pages = 405–409 | doi=10.1016/s0168-9525(97)01244-4| pmid = 9351342 }}</ref> Some of these changes appear to be common to various kinds of malignant tumors, while others are more tumor specific. For example, gains of chromosomal regions lq, 3q and 8q, as well as losses of 8p, 13q, 16q and 17p, are common to a number of tumor types, such as breast, ovarian, prostate, renal and bladder cancer (Figure. 3). Other alterations, such as 12p and Xp gains in testicular cancer, 13q gain 9q loss in bladder cancer, 14q loss in renal cancer and Xp loss in ovarian cancer are more specific, and might reflect the unique selection forces operating during cancer development in different organs.<ref name="Forozan,Karhu,Kononen,Kallioniemi,Kallioniemi" /> Array CGH is also frequently used in research and diagnostics of B cell malignancies, such as chronic lymphocytic leukemia.

====Chromosomal aberrations====
[[Cri du Chat]] (CdC) is a syndrome caused by a partial deletion of the short arm of chromosome 5.<ref name="Levy,Dunn,Kern,Hirschhorn,Kardon">{{cite journal | vauthors = Levy B, Dunn TM, Kern JH, Hirschhorn K, Kardon NB | year = 2002 | title = Delineation of the dup5q phenotype by molecular cytogenetic analysis in a patient with dup5q/del 5p (Cri du Chat) | journal = Am J Med Genet | volume = 108 | issue = 3| pages = 192–197 | doi=10.1002/ajmg.10261| pmid = 11891684 }}</ref> Several studies have shown that conventional CGH is suitable to detect the deletion, as well as more complex chromosomal alterations. For example, Levy et al. (2002) reported an infant with a cat-like cry, the hallmark of CdC, but having an indistinct karyotype. CGH analysis revealed a loss of chromosomal material from 5p15.3 confirming the diagnosis clinically. These results demonstrate that conventional CGH is a reliable technique in detecting structural aberrations and, in specific cases, may be more efficient in diagnosing complex abnormalities.<ref name="Levy,Dunn,Kern,Hirschhorn,Kardon" />