» Articles » PMID: 20101690

Two Siblings with Alternate Unbalanced Recombinants Derived from a Large Cryptic Maternal Pericentric Inversion of Chromosome 20

Overview
Specialty Genetics
Date 2010 Jan 27
PMID 20101690
Citations 4
Authors
Affiliations
Soon will be listed here.
Abstract

Two brothers, with dissimilar clinical features, were each found to have different abnormalities of chromosome 20 by subtelomere fluorescence in situ hybridization (FISH). The proband had deletion of 20p subtelomere and duplication of 20q subtelomere, while his brother was found to have a duplication of 20p subtelomere and deletion of 20q subtelomere. Parental cytogenetic studies were initially thought to be normal, both by G-banding and by subtelomere FISH analysis. Since chromosome 20 is a metacentric chromosome and an inversion was suspected, we used anchored FISH to assist in identifying a possible inversion. This approach employed concomitant hybridization of a FISH probe to the short (p) arm of chromosome 20 with the 20q subtelomere probe. We identified a cytogenetically non-visible, mosaic pericentric inversion of one of the maternal chromosome 20 homologs, providing a mechanistic explanation for the chromosomal abnormalities present in these brothers. Array comparative genomic hybridization (CGH) with both a custom-made BAC and cosmid-based subtelomere specific array (TEL array) and a commercially available SNP-based array confirmed and further characterized these rearrangements, identifying this as the largest pericentric inversion of chromosome 20 described to date. TEL array data indicate that the 20p breakpoint is defined by BAC RP11-978M13, approximately 900 kb from the pter; SNP array data reveal this breakpoint to occur within BAC RP11-978M13. The 20q breakpoint is defined by BAC RP11-93B14, approximately 1.7 Mb from the qter, by TEL array; SNP array data refine this breakpoint to within a gap between BACs on the TEL array (i.e., between RP11-93B14 and proximal BAC RP11-765G16).

Citing Articles

Short report: Twins with 20p13 duplication. Case report and comprehensive literature review.

Kennedy B, Savage S, Kaler S Mol Genet Genomic Med. 2024; 12(5):e2436.

PMID: 38738460 PMC: 11089493. DOI: 10.1002/mgg3.2436.


A novel de novo 20q13.32-q13.33 deletion in a 2-year-old child with poor growth, feeding difficulties and low bone mass.

Balasubramanian M, Atack E, Smith K, Parker M J Hum Genet. 2015; 60(6):313-7.

PMID: 25761574 DOI: 10.1038/jhg.2015.22.


A case of partial trisomy 20p resulting from meiotic recombination of a maternal pericentric inversion.

Kang J, Park M, Cheon C, Lee H, Hwang S, Yi J Ann Lab Med. 2012; 32(1):91-4.

PMID: 22259786 PMC: 3255494. DOI: 10.3343/alm.2012.32.1.91.


A genotype-first approach for the molecular and clinical characterization of uncommon de novo microdeletion of 20q13.33.

Traylor R, Bruno D, Burgess T, Wildin R, Spencer A, Ganesamoorthy D PLoS One. 2010; 5(8):e12462.

PMID: 20805988 PMC: 2929201. DOI: 10.1371/journal.pone.0012462.

References
1.
JOYCE C, Dennis N, Cooper S, Browne C . Subtelomeric rearrangements: results from a study of selected and unselected probands with idiopathic mental retardation and control individuals by using high-resolution G-banding and FISH. Hum Genet. 2001; 109(4):440-51. DOI: 10.1007/s004390100588. View

2.
Bena F, Bottani A, Marcelli F, Sizonenko L, Conrad B, Dahoun S . A de novo 1.1-1.6 Mb subtelomeric deletion of chromosome 20q13.33 in a patient with learning difficulties but without obvious dysmorphic features. Am J Med Genet A. 2007; 143A(16):1894-9. DOI: 10.1002/ajmg.a.31789. View

3.
Baroncini A, Rivieri F, Capucci A, Croci G, Franchi F, Sensi A . FISH screening for subtelomeric rearrangements in 219 patients with idiopathic mental retardation and normal karyotype. Eur J Med Genet. 2005; 48(4):388-96. DOI: 10.1016/j.ejmg.2005.05.002. View

4.
Roberts A, Cox G, Kimonis V, Lamb A, Irons M . Clinical presentation of 13 patients with subtelomeric rearrangements and a review of the literature. Am J Med Genet A. 2004; 128A(4):352-63. DOI: 10.1002/ajmg.a.30142. View

5.
Molina-Gomes D, Nebout V, Daikha-Dahmane F, Vialard F, Ville Y, Selva J . Partial trisomy 20p resulting from recombination of a maternal pericentric inversion: case report of a prenatal diagnosis by chorionic villus sampling. Prenat Diagn. 2006; 26(3):239-41. DOI: 10.1002/pd.1389. View