Analysis of 31 STR loci in the genetic isolate of Carloforte (Sardinia, Italy)

The genotypes of 31 autosomal short tandem repeat loci in the population of Carloforte were analyzed, these representing a linguistic and genetic isolate located on the island of Sardinia (Italy). The markers span the entire length of chromosomes 19, 20, 21 and 22. Allele frequencies and statistical parameters were presented for all loci. Observed heterozygosity ranged from 0.279 to 0.884, and polymorphism information content from 0.552 to 0.886. All but two loci showed Hardy-Weinberg equilibrium after Bonferroni correction. The 31 short tandem repeat loci examined in the present work provide additional data on the genetic structure of the Carloforte population

A Pentanucleotide Repeat Polymorphism (TTTTA) in the Apolipoprotein (a) Gene – Its Distribution and Its Association with the Risk of Cardiovascular Disease

Apolipoprotein (a) is a component of lipoprotein (a). Several studies have shown the association between risk of coronary heart diseases and the size of apo(a) isoforms, although this issue is still controversial. Recent researches focused the attention on the pentanucleotide (TTTTA), highlighting a statistical correlation between low Lp(a) levels and high repeat numbers. In the present paper we studied the distribution of the apo(a) pentanucleotide polymorphism among populations from Corsica, and we then compared it with other populations from Europe, Africa and Asia. The results stressed out the usefulness of these markers in population genetics analysis. We later investigated the possible association of the apo(a) pentanucleotide polymorphism with serum lipid levels in two samples from Corsica (France): one comprises patients or individuals with high risk of future coronary heart disease and the other is a control sample. No significant differences between the two groups have been found, but the analysis of variance showed a significant association between different genotypes and cholesterol and LDL serum levels

Worldwide variation of the COL14A1 gene is shaped by genetic drift rather than selective pressure

Background: The aim of this study is to analyze the worldwide distribution of SNP rs4870723 in COL14A1 gene to check if there are significant genetic differences among different populations and to test if the gene is a trait under selection. Methods: Genomic DNA was extracted from 69 unrelated individuals from Sardinia and genotyped for SNP rs4870723. Data were compared with 26 different populations, clustered in 5 super-populations, from the public 1000 genomes database. Allele frequency and heterozygosity were calculated with Genepop. The Hardy–Weinberg equilibrium and pairwise population differentiation through analysis of molecular variance (AMOVA FST) were determined with Arlequin. Results: Allele frequencies of COL14A1 rs4870723 were compared in 27 populations clustered in 5 super-populations. All populations were in the Hardy–Weinberg equilibrium. In almost all populations, allele C was the most frequent allele, reaching the highest values in East Asia. The 27 populations showed an appreciable structure, with significant differences observed between European, African, and Asian populations. Conclusion: Significant differences were observed in the rs4870723 SNP distribution among the populations studied. However, we found no evidence for a selective pressure. Rather, the differentiation among the populations is likely the result of founder effect, genetic drift, and cultural factors, all events known to establish and maintain genetic diversity between populations

Collagen Gene Variants and Anterior Cruciate Ligament Rupture in Italian Athletes: A Preliminary Report

Several studies have investigated the role of genetics in anterior cruciate ligament (ACL) rupture, often returning conflicting results. The present pilot study aimed to analyze the association between six Single Nucleotide Polymorphisms (SNPs) (rs1800012; rs12722; rs13946; rs240736; rs970547; and rs4870723, located on the COL1A1, COL5A1, COL12A1, and COL14A1 genes), and ACL rupture, among Italian athletes. A hypothesis-driven association study was conducted. In total, 181 male and female athletes (n = 86 injured; n = 96 non-injured) were genotyped for the prioritized variants. All polymorphisms were genotyped using PCR RFLP, with the only exception being the rs1800012 on the COL1A1 gene, which was detected using MTPA PCR. The allele frequency distribution fell within the worldwide range. Despite the evident population variability, no selective pressure signals were recorded using PBS analysis. No significant difference was detected between the cases and controls for any of the SNPs (rs1800012; rs13946; rs240736; rs970547, and rs4870723) included in the analyses (p > 0.008, Bonferroni-adjusted for multiple comparisons). Moreover, no significant differences were found when males and females were assessed separately. Further investigations based on a larger sample size are needed, in order to draw solid conclusions for the influence between collagen genes and ACL rupture. © 2023 by the authors

A Pentanucleotide Repeat Polymorphism (TTTTA) in the Apolipoprotein (a) Gene – Its Distribution and Its Association with the Risk of Cardiovascular Disease

Apolipoprotein (a) is a component of lipoprotein (a). Several studies have shown the association between risk of coronary heart diseases and the size of apo(a) isoforms, although this issue is still controversial. Recent researches focused the attention on the pentanucleotide (TTTTA), highlighting a statistical correlation between low Lp(a) levels and high repeat numbers. In the present paper we studied the distribution of the apo(a) pentanucleotide polymorphism among populations from Corsica, and we then compared it with other populations from Europe, Africa and Asia. The results stressed out the usefulness of these markers in population genetics analysis. We later investigated the possible association of the apo(a) pentanucleotide polymorphism with serum lipid levels in two samples from Corsica (France): one comprises patients or individuals with high risk of future coronary heart disease and the other is a control sample. No significant differences between the two groups have been found, but the analysis of variance showed a significant association between different genotypes and cholesterol and LDL serum levels

Overcoming the dichotomy between open and isolated populations using genomic data from a large European dataset

Human populations are often dichotomized into "isolated" and "open" categories using cultural and/or geographical barriers to gene flow as differential criteria. Although widespread, the use of these alternative categories could obscure further heterogeneity due to inter-population differences in effective size, growth rate, and timing or amount of gene flow. We compared intra and inter-population variation measures combining novel and literature data relative to 87,818 autosomal SNPs in 14 open populations and 10 geographic and/or linguistic European isolates. Patterns of intra-population diversity were found to vary considerably more among isolates, probably due to differential levels of drift and inbreeding. The relatively large effective size estimated for some population isolates challenges the generalized view that they originate from small founding groups. Principal component scores based on measures of intra-population variation of isolated and open populations were found to be distributed along a continuum, with an area of intersection between the two groups. Patterns of inter-population diversity were even closer, as we were able to detect some differences between population groups only for a few multidimensional scaling dimensions. Therefore, different lines of evidence suggest that dichotomizing human populations into open and isolated groups fails to capture the actual relations among their genomic features