Idiopathic mental retardation is a common condition the origins of which are poorly understood. Following initial reports that small chromosomal rearrangements affecting telomeres could be an important aetiological contributor, several new methods for screening patients have been developed. Over the past few years, 22 studies have reported results from 2585 patients. The prevalence of abnormali...

Recently, it was shown that gene conversion between the ends of linear mitochondrial chromosomes can cause telomere expansion and the duplication of subtelomeric loci. However, it is not yet known how widespread this phenomenon is and how significantly it has impacted organelle genome architecture. Using linear mitochondrial DNAs and mitochondrial plasmids from diverse eukaryotes, we argue that...

Telomeric regions contain prominent sites of heterochromatin, which is associated with unique histone modification profiles such as the methylation of histone H3 at Lys9 (H3K9me). In fission yeast, the conserved telomeric shelterin complex recruits the histone H3K9 methyltransferase complex CLRC to establish subtelomeric heterochromatin. Although many shelterin mutations affect subtelomeric het...

Material Supplemental http://genome.cshlp.org/content/suppl/2012/03/15/gr.136556.111.DC1.html References http://genome.cshlp.org/content/22/6/1036.full.html#ref-list-1 This article cites 41 articles, 11 of which can be accessed free at: License Commons Creative . http://creativecommons.org/licenses/by-nc/3.0/ described at a Creative Commons License (Attribution-NonCommercial 3.0 Unported Licens...

Mutations in the human DNA methyltransferase 3B (DNMT3B) gene lead to ICF (immunodeficiency, centromeric region instability, and facial anomalies) syndrome type I. We have previously described a telomere-related phenotype in cells from these patients, involving severe hypomethylation of subtelomeric regions, abnormally short telomeres and high levels of telomeric-repeat-containing RNA (TERRA). ...

72% of balanced spermatozoa (Figure 1). No further rearrangement involving chromosome 10 and 18 has been found. Hybridization with X, Y, 18, 13, and 21 chromosome probes revealed no significant increase of gametes with numerical abnormalities (data not shown). Microarray-based comparative genomic hybridization was performed using Agilent® oligonucleotide arrays according to the manufacturer’s i...

The etiology of mental retardation (MR), often presenting as developmental delay in childhood, is unknown in approximately one-half of cases. G-banding is the standard method for investigating those suspected of having a chromosomal etiology; however, detection of structural abnormalities is limited by the size and pattern of the G-bands involved. Rearrangements involving subtelomeric regions h...