Complete mitochondrial DNA profile in stroke: A geographical matched case-control study in Spanish population.

Introduction: Stroke, the second leading cause of death worldwide, is a complex disease influenced by many risk factors among which we can find reactive oxygen species (ROS). Since mitochondria are the main producers of cellular ROS, nowadays studies are trying to elucidate the role of these organelles and its DNA (mtDNA) variation in stroke risk. The aim of the present study was to perform a comprehensive evaluation of the association between mtDNA mutations and mtDNA content and stroke risk.

Mitochondrial DNA haplogroups J and T increase the risk of glioma.

The presence of different sets of mitochondrial polymorphisms generated by the accumulation of mutations in different maternal lineages has allowed differentiating mitochondrial haplogroups in human populations. These polymorphisms, in turn, may have effects at the phenotypic level, considering a possible contribution of these germinal mutations to the development of certain diseases such as cancer. The main goal of the present study is to establish a possible association between mitochondrial haplogroups and the risk of suffering glioma.

The role of control region mitochondrial DNA mutations in cardiovascular disease: stroke and myocardial infarction.

Recent studies associated certain type of cardiovascular disease (CVD) with specific mitochondrial DNA (mtDNA) defects, mainly driven by the central role of mitochondria in cellular metabolism. Considering the importance of the control region (CR) on the regulation of the mtDNA gene expression, the aim of the present study was to investigate the role of mtDNA CR mutations in two CVDs: stroke and myocardial infarction (MI). MtDNA CR mutations (both fixed and in heteroplasmy) were analysed in two demographically-matched case-control samples, using 154 stroke cases, 211 MI cases and their corresponding control individuals.

Sensitivity of mitochondrial DNA heteroplasmy detection using Next Generation Sequencing.

Although the use of Next Generation Sequencing (NGS) in mitochondrial DNA (mtDNA) studies related to forensic and human genetics has contributed to the report of heteroplasmy at very low levels (lower than 1% and even 0.5%), their detection is not a straightforward process. Our purpose is to establish mitochondrial heteroplasmy detection limits, generating mixed bases at low frequencies by the PCR co-amplification of mtDNA and a nuclear insertion of mitochondrial origin (NUMT).

Involvement of mitochondrial haplogroups in myocardial infarction and stroke: A case-control study in Castile and Leon (Spain) population.

There are strong evidences that common mitochondrial DNA (mtDNA) haplogroups may influence the pathogenesis of cardiovascular diseases (CVDs). In this matched case-control study, we investigate the association between mtDNA haplogroups and two CVDs, myocardial infarction (MI) and stroke, and classical cardiovascular risk factors. Data obtained show that haplogroup H constitute a susceptibility risk factor for MI (p=0.

Y-chromosome analysis in a Northwest Iberian population: unraveling the impact of Northern African lineages.

Objectives: To provide new clues about the genetic origin, composition and structure of the population of the Spanish province of Zamora, with an emphasis on the genetic impact of the period of Islamic rule in the Iberian Peninsula.

Methods: Polymorphisms in the paternally inherited Y-chromosome, Single Nucleotide Polymorphisms and Short Tandem Repeats, were analyzed in 235 unrelated males born in six different regions in the Zamora province.

Results: A relatively homogenous Y-chromosome haplogroup composition was observed in the Zamora province.

Molecular polymorphism of the ABO blood group: a study in Poland, Spain, and Andorra.

Objectives: The main goal of this study is to increase knowledge on the molecular level of the ABO blood group system in Europe by providing data for Poland, Spain, and Andorra populations.

Methods: A total of 172 oral scrapings samples from individuals of Polish origin, 108 peripheral blood samples of autochthonous individuals from the province of Zamora (Spain), and 81 peripheral blood samples from individuals with Andorran origin, were analyzed. Molecular characterization of the allelic variants was performed by the analysis of exons 6 and 7 of the ABO gene.

Mitochondrial DNA and Y-chromosome structure at the Mediterranean and Atlantic façades of the Iberian Peninsula.

Objectives: The aim of this study is to analyze mitochondrial DNA and Y-chromosome lineages in a range of Atlantic and Mediterranean populations of the Iberian Peninsula in search of genetic differences between both façades and to uncover the most probable geographic origin and coalescence ages of lineages.

Methods: The control region of mitochondrial DNA and haplogroup diagnostic positions were analyzed in 575 subjects and Y-chromosome markers were typed in 260 unrelated males. Moreover, previously published data were compiled and used in the analyses.

Frequency and pattern of heteroplasmy in the complete human mitochondrial genome.

Determining the levels of human mitochondrial heteroplasmy is of utmost importance in several fields. In spite of this, there are currently few published works that have focused on this issue. In order to increase the knowledge of mitochondrial DNA (mtDNA) heteroplasmy, the main goal of this work is to investigate the frequency and the mutational spectrum of heteroplasmy in the human mtDNA genome.

Linguistic isolates in Portugal: insights from the mitochondrial DNA pattern.

Miranda do Douro, located in the northeastern region of Portugal, has notable characteristics not only from a geographic or naturalistic point of view, but also from a cultural perspective. A remarkable one is the coexistence of two different languages: Portuguese and Mirandese, the second being an Astur-Leonese dialect. The current persistence of the Astur-Leonese dialect in this population falls on the singularity of the region: relative isolation, implying difficulties to communicate with other Portuguese regions, while the same location facilitated the establishment of social and commercial relationships with adjacent Spanish territories, origin of the Astur-Leonese language.

Primer effect in the detection of mitochondrial DNA point heteroplasmy by automated sequencing.

The correct detection of mitochondrial DNA (mtDNA) heteroplasmy by automated sequencing presents methodological constraints. The main goals of this study are to investigate the effect of sense and distance of primers in heteroplasmy detection and to test if there are differences in the accurate determination of heteroplasmy involving transitions or transversions. A gradient of the heteroplasmy levels was generated for mtDNA positions 9477 (transition G/A) and 15,452 (transversion C/A).

Tracing the origin of the east-west population admixture in the Altai region (Central Asia).

A recent discovery of Iron Age burials (Pazyryk culture) in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia. Studies on ancient mitochondrial DNA of this region suggest that the Altai Mountains played the role of a geographical barrier between West and East Eurasian lineages until the beginning of the Iron Age. After the 7th century BC, coinciding with Scythian expansion across the Eurasian steppes, a gradual influx of East Eurasian sequences in Western steppes is detected.

Nuclear insertions of mitochondrial origin: Database updating and usefulness in cancer studies.

Nuclear insertions of mitochondrial origin (NUMTs) can be useful tools in evolution and population studies. However, due to their similarity to mitochondrial DNA (mtDNA), NUMTs may also be a source of contamination in mtDNA studies. The main goal of this work is to present a database of NUMTs, based on the latest version of the human genome-GRCh37 draft.

Validated primer set that prevents nuclear DNA sequences of mitochondrial origin co-amplification: a revision based on the New Human Genome Reference Sequence (GRCh37).

A new human genome reference sequence--GRCh37--was recently generated and made available by the Genome Reference Consortium. Since the prior disposable human reference sequence--hg18--was previously used for the mitochondrial DNA primer BLAST validation, a revision of those previously published primer pairs is required. Thus, the aim of this Short Communication is to perform an in silico BLAST test of the published disposable nine primer pairs using the new human reference sequence and to report the pertinent modifications.

Mitochondrial DNA patterns in the Iberian Northern plateau: population dynamics and substructure of the Zamora province.

Several studies have shown the importance of recent events in the configuration of the genetic landscape of a specific territory. In this context, due to the phenomena of repopulation and demographic fluctuations that took place in recent centuries, the Iberian Northern plateau is a very interesting case study. The main aim of this work is to check if recent population movements together with existing boundaries (geographical and administrative) have influenced the current genetic composition of the area.

Genetic structure of the Azores Islands: a study using 15 autosomal short tandem repeat loci.

The Azores archipelago (Portugal), located in the Atlantic Ocean, 1,500 km from the European mainland, is formed by nine islands of volcanic origin. The relative position of these islands allows the definition of three geographical groups: Eastern, Central and Western. Previous studies of the Azores using Short Tandem Repeats (STRs) have highlighted differences in the frequencies of several loci, when compared to Mainland Portugal or Madleira Island.

Human mitochondrial DNA complete amplification and sequencing: a new validated primer set that prevents nuclear DNA sequences of mitochondrial origin co-amplification.

To date, there are no published primers to amplify the entire mitochondrial DNA (mtDNA) that completely prevent the amplification of nuclear DNA (nDNA) sequences of mitochondrial origin. The main goal of this work was to design, validate and describe a set of primers, to specifically amplify and sequence the complete human mtDNA, allowing the correct interpretation of mtDNA heteroplasmy in healthy and pathological samples. Validation was performed using two different approaches: (i) Basic Local Alignment Search Tool and (ii) amplification using isolated nDNA obtained from sperm cells by differential lyses.

Y-chromosome variation in South Iberia: insights into the North African contribution.

Population of Pedroches Valley, a hypothetical Berber settlement, located in the northwest portion of Córdoba province (Andalusia, Spain), had been analyzed for its Y-chromosome diversity. Moreover, to contextualize this population, 127 Y-chromosomes from a general Andalusia sample and a North African Berber community (Marrakech, Morocco) were also typed. For all samples, 24 single nucleotide polymorphisms of the non-recombining portion of the Y-chromosome (NRY) were analyzed and those samples described as belonging to E3b1b-M81 haplogroup were also typed for 16 Y-chromosome short tandem repeats.

Frequency and pattern of heteroplasmy in the control region of human mitochondrial DNA.

In this work, we present the results of the screening of human mitochondrial DNA (mtDNA) heteroplasmy in the control region of mtDNA from 210 unrelated Spanish individuals. Both hypervariable regions of mtDNA were amplified and sequenced in order to identify and quantify point and length heteroplasmy. Of the 210 individuals analyzed, 30% were fully homoplasmic and the remaining presented point and/or length heteroplasmy.

Mutation patterns of mtDNA: empirical inferences for the coding region.

Background: Human mitochondrial DNA (mtDNA) has been extensively used in population and evolutionary genetics studies. Thus, a valid estimate of human mtDNA evolutionary rate is important in many research fields. The small number of estimations performed for the coding region of the molecule, showed important differences between phylogenetic and empirical approaches.