Loss of Heterozygosity on Chromosomes 1, 2, 8, 9 and 17 in Cerebral Atherosclerotic plaques

Objective

Atherosclerosis is a fibroproliferative disease which has been attributed to several factors including genetic and molecular alterations. Initial studies have shown genetic alterations at the microsatellite level in the DNA of atherosclerotic plaques. Extending our initial findings, we performed a microsatellite analysis on cerebral atherosclerotic plaques.

Methods

Twenty-seven cerebral atherosclerotic plaques were assessed for loss of heterozygosity (LOH) and microsatellite instability (MI) using 25 microsatellite markers located on chromosomes 2, 8, 9 and 17. DNA was extracted from the vessels as well as the respective blood from each patient and subjected to polymerase chain reaction.

Results

Our analyses revealed that specific loci on chromosomes 2, 8, 9 and 17 exhibited a significant incidence of LOH. Forty-six percent of the specimens showed loss of heterozygosity at 2p13–p21, 48% exhibited LOH at 8p12–q11.2, while allelic imbalance was detected in 47% of the cases. The LOH incidence was 39%, 31% and 27% at 17q21, 9q31–34 and 17p13, respectively. Genetic alterations were detected at a higher rate as compared to the corresponding alterations observed in plaques from other vessels.

Discussion

This is the first microsatellite analysis using atherosclerotic plaques obtained from cerebral vessels. Our results indicate an elevated mutational rate on specific chromosomal loci, suggesting a potential implication of these regions in atherogenesis.

A global analysis of Y-chromosomal haplotype diversity for 23 STR loci

In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.