Chromosome rearrangements are a significant cause of intellectual disability and birth defects. Subtelomeric rearrangements, including deletions, duplications and translocations of chromosome ends, were first discovered over 40 years ago and are now recognized as being responsible for several genetic syndromes. Unlike the deletions and duplications that cause some genomic disorders, subtelomeri...

Rearrangements of the subtelomeric regions of chromosomes account for a significant proportion of the underlying genetic defects in both idiopathic mental retardation (MR) and multiple congenital anomalies. To detect the rearrangements, a set of subtelomeric fluorescence in situ hybridization (FISH) probes has been developed. The aim of this study was to reveal the frequency of subtelomeric rea...

The transcription of genes located in subtelomeric regions of yeast chromosomes is repressed relative to the rest of the genome. This repression requires wild-type nucleosome levels but not the telomere silencing factors Sir2, Sir3, Sir4, and Rap1. Subtelomeric heterochromatin is characterized by the absence of acetylation or methylation of histone H3 lysine residues, but it is not known whethe...

Tetrahymena telomeres usually consist of approximately 250 base pairs of T(2)G(4) repeats, but they can grow to reach a new length set point of up to 900 base pairs when kept in log culture at 30 degrees C. We have examined the growth profile of individual macronuclear telomeres and have found that the rate and extent of telomere growth are affected by the subtelomeric region. When the sequence...

Chz1p is a histone chaperone that interacts physically and functionally with the histone variant Htz1p, which has been implicated in establishing and maintaining boundaries between transcriptionally inactive heterochromatin and active euchromatin. To investigate the role of Chz1p in chromatin organization, we performed genome-wide expression arrays and chromatin immunoprecipitations of SIR comp...

Recent studies have shown that cryptic unbalanced subtelomeric rearrangements contribute to a significant proportion of idiopathic syndromic mental retardation cases. Using a fluorescent genotyping based strategy, we found a 10% rate of cryptic subtelomeric rearrangements in a large series of 150 probands with severe idiopathic syndromic mental retardation and normal RHG-GTG banded karyotype. F...

BACKGROUND Subtelomeric regions of the human genome are gene rich, with a high level of sequence polymorphism. A number of clinical conditions, including learning disability, have been attributed to subtelomeric deletions or duplications, but screening for deletion in these regions using conventional cytogenetic methods and fluorescence in situ hybridisation (FISH) is laborious. Here we report ...

A chromosome is composed of structurally and functionally distinct domains. However, the molecular mechanisms underlying the formation of chromatin structure and the function of subtelomeres, the telomere-adjacent regions, remain obscure. Here we report the roles of the conserved centromeric protein Shugoshin 2 (Sgo2) in defining chromatin structure and functions of the subtelomeres in the fiss...

The process of meiosis results in the formation of haploid daughter cells, each of which inherit a half of the diploid parental cells' genetic material. The ordered association of homologues (identical chromosomes) is a critical prerequisite for a successful outcome of meiosis. Homologue recognition and pairing are initiated at the chromosome ends, which comprise the telomere dominated by gener...

CONTEXT Unbalanced subtelomeric chromosomal rearrangements are often associated with intellectual disability (ID) and malformation syndromes. The prevalence of such rearrangements has been reported to be 5-9% in ID populations. AIMS To study the prevalence of subtelomeric rearrangements in the Indonesian ID population. MATERIALS AND METHODS We tested 436 subjects with unexplained ID using m...