Dainis Ruņģis, Anna Korica, Agnese Gailīte, Ilze Pušpure and Ilze Veinberga
Common ash (Fraxinus excelsior L.) has a widespread distribution throughout Europe, and Latvia is almost at the north eastern edge of the distribution range. In Europe, ash is threatened by ash dieback, a disease caused by the introduced ascomycete Hymenoscyphus fraxineus. Chloroplast and nuclear DNA markers have been used to study the genetic diversity and population structure of ash both in a broader pan-European context as well as in more restricted regions. Some of the markers analysed in these previously published reports were also utilised in this study, enabling comparisons of the genetic parameters calculated from the nuclear SSR marker data and of the haplotypes identified with the chloroplast markers. Analysis of chloroplast markers revealed one dominant haplotype in Latvian stands, which corresponds to the haplotype previously found in Eastern Europe and Scandinavia. A second haplotype, corresponding to a previously reported central European haplotype was found in all individuals from the Ķemeri stand, indicating that this stand was naturally established from introduced germplasm, which was planted in a neighbouring park. The nuclear SSR markers revealed low levels of differentiation of Latvian F. excelsior stands, probably due efficient pollen flow between stands. The analysis of both chloroplast and nuclear DNA markers has revealed different aspects of the structure and provenance of Latvian F. excelsior populations.
A Zarina, I Tolmane, Z Krumina, AI Tutane and L Gailite
Wilson’s disease (WD) is a copper metabolism disorder, caused by allelic variants in the ATP7B gene. Wilson’s disease can be diagnosed by clinical symptoms, increased copper and decreased cerulopasmin levels, which could all also be by other genetic variants beyond the ATP7B gene, e.g., disturbed ceruloplasmin biosynthesis can be caused by pathogenic allelic variants of the CP gene. Copper metabolism in the organism is affected by several molecules, but pathogenic variants and related phenotypes are described with COMMD1 and ATOX1 genes. The aim of the study was to test other genes, CP, ATOX1 and COMMD1, for possible influence to the manifestation of WD. Patients were enrolled on the basis of Leipzig’s diagnostic criteria, 64 unrelated patients with confirmed WD. Direct sequencing of promoter region of the CP gene and ATOX1 and COMMD1 gene exons was conducted. Statistically significant differences were found between the two variants in the CP gene and the ATP7B genotype (rs66508328 variant AA genotype and the rs11708215 variant GG genotype) were more common in WD patients with an unconfirmed ATP7B genotype. One allelic (intronic) variant was found in the ATOX1 gene without causing the functional changes of the gene. Three allelic variants were identified in the COMMD1 gene. No statistically significant differences were found between allele and genotype frequencies and the first clinical manifestations of WD. Different variants of the CP gene contributed to a WD-like phenotype in clinically confirmed WD patients with neurological symptoms and without identified pathogenic variants in the ATP7B gene. Allelic variants in the ATOX1 and COMMD1 genes do not modify the clinical manifestation of WD in Latvian patients. (266 words)
Jurgita Gailite, Agnese Mikilpa-Mikgelba, Ieva Siliņa, Ināra Kirillova, Una Lauga-Tuņina, Iveta Dzīvīte-Krišāne and Dace Gardovska
The world has seen a rise of type 2 diabetes mellitus in children during the last 20 years. It is proposed that this increase is due to unhealthy eating habits, increasing obesity, especially among teenagers, and better diagnostics. The main risks associated with diabetes are microvascular and macrovascular complications, which can lead to early disability and premature death. The aim of our study was to identify children with type 2 diabetes mellitus or impaired glucose tolerance and investigate associated comorbidities at the time of diagnosis in the Children’s Clinical University Hospital in Latvia. A retrospective analysis was performed of all children with type 2 diabetes mellitus or glucose tolerance impairment from 2002 till 2013, who were treated in Children’s Endocrinology Centre. According to inclusion criteria, 57 patients were selected of whom 24 (42%) had type 2 diabetes mellitus and 33 (58%) had impaired glucose tolerance. Body mass index was analysed according to percentile and all patients were found to have excess weight. In children with type 2 diabetes mellitus, all patients had body mass index over the 99th percentile. Arterial hypertension was found in 66.7% and dyslipidemia in 54.2% type 2 diabetes mellitus patients. From all type 2 diabetes mellitus patients, 71% (n = 17) were girls and they had statistically significantly higher total cholesterol (p = 0.02) and low-density lipoprotein (p = 0.003) levels. Considering, that girls with type 2 diabetes mellitus have high cardiovascular risk in adulthood, it is very important not only to achieve normal glucose levels early, but also to treat comorbidities, to reduce further microvascular and macrovascular complication risk.
Astrīda Krūmiņa, Liāna Pliss, Gunita Zariņa, Agrita Puzuka, Agnese Zariņa, Baiba Lāce, Didzis Elferts, Andrey Khrunin, Svetlana Limborska, Jānis Kloviņš and Linda Gailīte Piekuse
This article presents a review on population genetics of Latvians, which alongside Lithuanians are the two extant Baltic speaking populations. The article provides a description of genome-wide single nucleotide polymorphism (SNP) data and contains a comparative analysis of the results of studies performed on classical autosomal genetic markers, mitochondrial DNA (mtDNA) and the non-recombining part of the Y chromosome (NRY), with data on neighbouring populations. The study also covers data of recently performed ancient DNA (aDNA) studies carried out on samples from the territory of today’s Latvia. The results of population genetic studies have shown a mixture of eastern and western genetic traits in present-day Latvians with only small differences between Latvian subpopulations. Studies of the Baltic “tribal gene” LWb, as well as the gene’s SERPINA1 allele PIZ have indicated the presence of a considerable Baltic admixture in the neighbouring Finno-Ugric and Slavic populations. Although mtDNA analyses have shown that Latvians genetically in general belong to the same common gene pool as most of the Europeans, the Y-chromosomal lineage composition suggests that they are most similar to Northern and Eastern European populations of Lithuanians, Estonians, and Eastern-Slavic populations, which are ethnogenetically closest to them. The analysis of aDNA from the Early and Middle Neolithic did not present any genomic evidence of gene-flow from Central European farmers or any mitochondrial or Y-chromosomal haplogroups that are typical for them in the hunter-gatherers from the territory of today’s Latvia and Lithuania.
Agnese Gailīte, Anita Gaile, Ilze Gaile, Angelika Voronova, Ilze Veinberga, Aina Kokare and Dainis Edgars Ruņģis
Rye (Secale cereale L.) is an important grain crop in Latvia, where it is mainly used for baking rye bread, which is a popular staple. However, the area under rye cultivation in Latvia is small, and the majority of varieties planted are foreign. In 1937, almost 290 000 ha of rye were planted, while in 2011, only 28 000 ha were planted, or ~5% of the area planted with cereals. The Latvian rye genetic resources collection contains nine accessions, including old and new cultivars, landraces and one repatriated accession, which was previously held in the N. I. Vavilov Research Institute of Plant Industry collection. A set of descriptors has been developed for rye, and field evaluations of the Latvian rye collection have been started. A set of simple sequence repeat (SSR) markers has been utilised for genetic fingerprinting of the collection. The initial genetic results indicate that the Latvian rye collection contains a high degree of genetic diversity. Analyses are continuing in order to more fully characterise the collection both phenotypically and genetically.