title: Autosomal ring chromosomes in human genetic disorders.
abstract: Ring chromosomes arise following breakage and rejoining in both chromosome arms. They are heterogeneous with variable size and genetic content and can originate from any chromosome. Phenotypes associated with ring chromosomes are highly variable as apart from any deletion caused by ring formation, imbalances from ring instability can also occur. Of interest is ring chromosome 20 which has a significant association with epilepsy with seizure onset in early childhood. Severe growth deficiency without major malformations is a common finding in the ring chromosome carrier. This phenotype associated with ring behaviour and mitotic instability and independent of the chromosome involved has been termed the "ring syndrome". Precise genotype-phenotype correlations for ring chromosomes may not be possible as influencing factors vary depending on the extent of deletion in ring formation, ring instability and the level of mosaicism. Although ring chromosomes usually arise as de novo events, familial transmission of rings from carrier to offspring has been described and prenatal diagnosis for any pregnancies should always be considered.
authors.affiliation: SEALS Genetics Laboratory, NSW Health Pathology, Prince of Wales Hospital, Randwick, Sydney, NSW 2031, Australia.
authors.forename: Moh-Ying
authors.initials: MY
authors.lastname: Yip
keywords: Ring syndrome; dicentric; genetic counseling; mosaic; telomere
references.citation: J Med Genet. 2011 Jan;48(1):1-9
references.pmid: 20972251
references.citation: J Med Genet. 1977 Feb;14(1):54-60
references.pmid: 839502
references.citation: Clin Genet. 2009 Sep;76(3):256-62
references.pmid: 19793054
references.citation: Epigenetics Chromatin. 2014 Jan 07;7(1):1
references.pmid: 24393457
references.citation: Hum Genet. 1991 Jul;87(3):320-4
references.pmid: 1864607
references.citation: Clin Genet. 1991 Feb;39(2):151-5
references.pmid: 2015696
references.citation: BMC Med Genet. 2010 Oct 12;11:146
references.pmid: 20939888
references.citation: Am J Med Genet. 2001 Jul 1;101(3):226-39
references.pmid: 11424138
references.citation: Am J Med Genet. 1990 Feb;35(2):269-73
references.pmid: 2178418
references.citation: Am J Med Genet. 1999 Jul 16;85(2):117-22
references.pmid: 10406663
references.citation: Cytogenet Genome Res. 2014;144(1):1-8
references.pmid: 25171325
references.citation: Am J Med Genet A. 2008 Apr 1;146A(7):925-9
references.pmid: 18302251
references.citation: J Med Genet. 1994 Oct;31(10):804-6
references.pmid: 7837258
references.citation: Am J Med Genet A. 2004 Sep 1;129A(3):316-20
references.pmid: 15326636
references.citation: Am J Med Genet A. 2009 Jun;149A(6):1116-24
references.pmid: 19441122
references.citation: Hum Genet. 1993 Aug;92(1):23-7
references.pmid: 8365723
references.citation: Case Rep Genet. 2011;2011:158086
references.pmid: 23074672
references.citation: J Med Genet. 1977 Jun;14(3):228-32
references.pmid: 881718
references.citation: Hum Genet. 1987 Feb;75(2):174-9
references.pmid: 3817812
references.citation: Epilepsia. 2013 Dec;54(12):2204-13
references.pmid: 24116895
references.citation: Taiwan J Obstet Gynecol. 2012 Mar;51(1):71-6
references.pmid: 22482972
references.citation: BMC Med Genet. 2011 Dec 21;12:171
references.pmid: 22188645
references.citation: Prenat Diagn. 1995 Mar;15(3):269-73
references.pmid: 7784385
references.citation: Am J Dis Child. 1973 Aug;126(2):257-60
references.pmid: 4125054
references.citation: Ann Genet. 1981;24(4):231-5
references.pmid: 6977305
references.citation: Am J Med Genet. 1999 Dec 22;87(5):384-90
references.pmid: 10594875
references.citation: Am J Med Genet. 1983 Dec;16(4):563-73
references.pmid: 6660249
references.citation: Am J Med Genet. 1988 Jan;29(1):149-54
references.pmid: 3278612
references.citation: J Med Genet. 1995 Jun;32(6):486-7
references.pmid: 7545237
references.citation: Hum Genet. 1990 Oct;85(5):516-20
references.pmid: 2227937
references.citation: J Med Genet. 1996 Sep;33(9):789-92
references.pmid: 8880584
references.citation: Am J Med Genet. 1991 Jan;38(1):74-9
references.pmid: 1849352
references.citation: Lancet. 1966 Mar 26;1(7439):679-82
references.pmid: 4159599
references.citation: J Med Genet. 1981 Jun;18(3):209-13
references.pmid: 7241544
references.citation: Hum Genet. 1983;63(3):294-6
references.pmid: 6852827
references.citation: Ann Genet. 2004 Jul-Sep;47(3):289-96
references.pmid: 15337475
references.citation: J Med Genet. 2008 Nov;45(11):766-8
references.pmid: 18978335
references.citation: J Med Genet. 1982 Dec;19(6):471-3
references.pmid: 7154048
references.citation: J Med Genet. 1991 Aug;28(8):536-8
references.pmid: 1920370
references.citation: Mol Psychiatry. 2005 Aug;10(8):741-6
references.pmid: 15940295
references.citation: Am J Med Genet A. 2005 Aug 30;137(2):139-47
references.pmid: 16059935
references.citation: Clin Genet. 1978 Jul;14(1):8-15
references.pmid: 679524
references.citation: Clin Genet. 2002 Nov;62(5):415-7
references.pmid: 12431259
references.citation: Eur J Hum Genet. 2007 May;15(5):548-55
references.pmid: 17342151
references.citation: J Med Genet. 2002 Apr;39(4):e17
references.pmid: 11950869
references.citation: Hum Genet. 1989 Sep;83(2):148-54
references.pmid: 2777254
references.citation: J Med Genet. 2008 Mar;45(3):147-54
references.pmid: 18006671
references.citation: Fertil Steril. 2008 Nov;90(5):2004.e1-5
references.pmid: 18371955
references.citation: Prenat Diagn. 1995 Sep;15(9):872-4
references.pmid: 8559761
references.citation: Am J Med Genet. 2001 Dec 1;104(3):257-9
references.pmid: 11754054
references.citation: Eur J Med Genet. 2005 Jul-Sep;48(3):310-8
references.pmid: 16179226