Genome-wide single nucleotide polymorphism analysis has revealed large-scale cryptic regions of acquired homozygosity in the form of segmental uniparental disomy in approximately 20% of acute myeloid leukemias. We have investigated whether such regions, which are the consequence of mitotic recombination, contain homozygous mutations in genes known to be mutational targets in leukemia. In 7 of 1...

We describe a 17 year old male with a low level of trisomy 9 mosaicism. Maternal uniparental chromosome 9 disomy in the euploid cell line was shown to have arisen after postzygotic loss of the paternal chromosome 9 from the trisomic cell line by cytogenetic and molecular analysis. This is believed to be the first report of uniparental disomy for chromosome 9. In four of the 11 reported cases of...

The systematic application of new genome-wide single nucleotide polymorphism arrays has demonstrated that somatically acquired regions of loss of heterozygosity without changes in copy number frequently occur in many types of cancer. Until recently, the ubiquity of this type of chromosomal defect had gone unrecognized because it cannot be detected by routine cytogenetic technologies. Random and...

In the diploid cells of most organisms, including humans, each chromosome is usually distinguishable from its partner homolog by multiple single-nucleotide polymorphisms. One common type of genetic alteration observed in tumor cells is uniparental disomy (UPD), in which a pair of homologous chromosomes are derived from a single parent, resulting in loss of heterozygosity for all single-nucleoti...

OBJECTIVE Prader-Willi Syndrome is a common etiology of syndromic obesity that is typically caused by either a paternal microdeletion of a region in chromosome 15 (microdeletions) or a maternal uniparental disomy of this chromosome. The purpose of this study was to describe the most significant clinical features of 35 Brazilian patients with molecularly confirmed Prader-Willi syndrome and to de...