We previously showed by cytogenetics and fluorescence in situ hybridization (FISH) that the most common chromosomal abnormality in renal oncocytomas is loss of chromosome 1 or 1p. In the present study, we evaluated chromosome 1 by loss of heterozygosity (LOH) studies. DNA was extracted from paraffin sections. Three microsatellite markers were used: D1S508, D1S199, and D1S2734. The regions targe...

Rearrangements involving the MLL gene at chromosome 11q23 are associated with leukemia and are present in up to 70% of infant leukemias. Loss of heterozygosity (LOH) has been shown for anonymous polymorphic markers at 11q23 in adult leukemias. To study LOH at the MLL locus, we have identified two new polymorphic microsatellite markers: a GAA repeat (mllGAAn) in intron 6 of the MLL gene and a GA...

To determine the types of mutations induced by oxidative damage, a kidney cell line with a heterozygous deficiency for the autosomal Aprt (adenine phosphoribosyltransferase) gene was tested for its mutagenic response to hydrogen peroxide. Aprt-deficient cells were selected and scored for loss of heterozygosity (LOH) for 11 microsatellite loci on mouse chromosome 8. On the basis of the LOH analy...

Mutation and recombination are the major sources of genetic diversity in all organisms. In the baker's yeast, all mutation rate estimates are in homozygous background. We determined the extent of genetic change through mutation and loss of heterozygosity (LOH) in a heterozygous Saccharomyces cerevisiae genome during successive vegetative and meiotic divisions. We measured genome-wide LOH and ba...

AIMS To examine the clonal origin of a tumour, made up of a neuroendocrine component and a papillary serous component by comparing the pattern of loss of heterozygosity (LOH) and the immunohistochemical protein expression of both components. METHODS/RESULTS A 70 year old woman, known to have a metastasised neuroendocrine carcinoma, underwent resection of the distal part of the ileum because o...

Loss of heterozygosity (LOH) has been established as an important genetic mechanism giving rise to malignant neoplasia. The mechanism of LOH has been shown to cause basal cell carcinoma and malignant melanoma as well as other types of skin cancer. A few studies on LOH in sporadic keratoacanthomas have been reported. The purpose of this study was to investigate the significance of LOH in the pat...

We explored the feasibility of studying loss of heterozygosity (LOH) by using exome sequencing and compared the differences in genetic LOH between primary breast tumors and metastatic lesions. Exome sequencing was conducted to investigate the genetic LOH in the peripheral blood, a primary tumor, and a metastatic lesion from the same patient. LOH was observed in 30 and 48 chromosomal loci of the...

PURPOSE To define more clearly the role of the tumor suppressor gene p16 in uveal melanoma by determining the relative contribution of all known mechanisms of p16 inactivation in this tumor. METHODS A comprehensive genetic analysis of the p16 gene was performed in 33 primary sporadic ciliochoroidal and choroidal melanomas. Fourteen highly polymorphic microsatellite markers surrounding the p16...

We have undertaken an extensive high-resolution analysis of loss of heterozygosity (LOH) in 30 high grade gliomas using the Affymetrix 100K SNP mapping array. Only 70% of LOH events were accompanied by a copy number loss (CNA(loss)), and of the other 30%, the distal region of 17p preferentially showed copy number neutral (CNN)-associated LOH. Combined analysis of CNA(loss) and LOH using MergeLe...

To refine the chromosomal localization of a putative tumor suppressor gene, we analyzed the loss of heterozygosity (LOH) of chromosome 12 in 36 primary non-small cell lung cancer (NSCLC) samples with matched normal DNA using 22 highly informative polymorphic markers. Twelve cases showed LOH at one or more loci on chromosome 12. LOH of chromosome arm 12p was more frequent in large cell carcinoma...