Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
2.
J Appl Physiol (1985) ; 125(4): 972-982, 2018 10 01.
Article in English | MEDLINE | ID: mdl-29517423

ABSTRACT

Heritability studies using the twin model have provided the basis to disentangle genetic and environmental factors that contribute to several complex human traits. However, the relative importance of these factors to individual differences in proprioception is largely unknown despite the fact that proprioceptive senses are of great importance, allowing us to respond to stimuli stemming from the space around us and react to altering circumstances. Hence, a total of 44 healthy male twins (11 MZ and 11 DZ pairs), 19-28 yr old, were examined for movement, position, and force sense at the elbow joint, and their heritability estimates were computed. Results showed that genetic factors explained 1) 72 and 76% of the total variance of movement sense at the start and the end of the movement, respectively, 2) 60 to 77% of the total variance of position sense, depending on the angle of elbow flexion and whether forearm positioning was active or passive, and 3) 73 and 70% of the total variance of the force sense at 90 and 60° of elbow flexion, respectively. It is concluded that proprioception assessed by these conscious sensations is to a substantial degree genetically dependent, with heritability indexes ranging from 0.60 to 0.77, depending on the task. NEW & NOTEWORTHY Proprioceptive acuity varies among people, but it is not known how much of this variability is due to differences in their genes. This study is the first to report that proprioception, expressed as movement sense, position sense, and force sense, is substantially heritable, and it is conceivable that this may have implications for motor learning and control, neural development, and neurorehabilitation.


Subject(s)
Proprioception/genetics , Adult , Humans , Male , Quantitative Trait, Heritable , Young Adult
3.
BMC Genomics ; 18(Suppl 8): 835, 2017 Nov 14.
Article in English | MEDLINE | ID: mdl-29143595

ABSTRACT

While the influence of nature (genes) and nurture (environment) on elite sporting performance remains difficult to precisely determine, the dismissal of either as a contributing factor to performance is unwarranted. It is accepted that a complex interaction of a combination of innumerable factors may mold a talented athlete into a champion. The prevailing view today is that understanding elite human performance will require the deciphering of two major sources of individual differences, genes and the environment. It is widely accepted that superior performers are endowed with a high genetic potential actualised through hard and prodigious effort. Heritability studies using the twin model have provided the basis to disentangle genetic and environmental factors that contribute to complex human traits and have paved the way to the detection of specific genes for elite sport performance. Yet, the heritability for most phenotypes essential to elite human performance is above 50% but below 100%, meaning that the environment is also important. Furthermore, individual differences can potentially also be explained not only by the impact of DNA sequence variation on biology and behaviour, but also by the effects of epigenetic changes which affect phenotype by modifying gene expression. Despite this complexity, the overwhelming and accumulating evidence, amounted through experimental research spanning almost two centuries, tips the balance in favour of nature in the "nature" and "nurture" debate. In other words, truly elite-level athletes are built - but only from those born with innate ability.


Subject(s)
Athletes , Athletic Performance , Gene-Environment Interaction , Exercise , Genomics , Humans
4.
Med Sport Sci ; 61: 55-67, 2016.
Article in English | MEDLINE | ID: mdl-27287077

ABSTRACT

Despite numerous attempts to discover genetic variants associated with elite athletic performance, an individual's trainability and injury predisposition, there has been limited progress to date. Past reliance on candidate gene studies focusing predominantly on genotyping a limited number of genetic variants in small, often heterogeneous cohorts has not generated results of practical significance. Hypothesis-free genome-wide approaches will in the future provide more comprehensive coverage and in-depth understanding of the biology underlying sports-related traits and related genetic mechanisms. Large, collaborative projects with sound experimental designs (e.g. clearly defined phenotypes, considerations and controls for sources of variability, and necessary replications) are required to produce meaningful results, especially when a hypothesis-free approach is used. It remains to be determined whether the novel approaches under current implementation will result in findings with real practical significance. This review will briefly summarize current and future directions in exercise genetics and genomics.


Subject(s)
Adaptation, Physiological/genetics , Athletic Performance , Genomics , Biomedical Research , Exercise , Genotype , Humans , Phenotype , Physical Conditioning, Human
5.
Physiol Genomics ; 48(3): 183-90, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26715623

ABSTRACT

Despite numerous attempts to discover genetic variants associated with elite athletic performance, injury predisposition, and elite/world-class athletic status, there has been limited progress to date. Past reliance on candidate gene studies predominantly focusing on genotyping a limited number of single nucleotide polymorphisms or the insertion/deletion variants in small, often heterogeneous cohorts (i.e., made up of athletes of quite different sport specialties) have not generated the kind of results that could offer solid opportunities to bridge the gap between basic research in exercise sciences and deliverables in biomedicine. A retrospective view of genetic association studies with complex disease traits indicates that transition to hypothesis-free genome-wide approaches will be more fruitful. In studies of complex disease, it is well recognized that the magnitude of genetic association is often smaller than initially anticipated, and, as such, large sample sizes are required to identify the gene effects robustly. A symposium was held in Athens and on the Greek island of Santorini from 14-17 May 2015 to review the main findings in exercise genetics and genomics and to explore promising trends and possibilities. The symposium also offered a forum for the development of a position stand (the Santorini Declaration). Among the participants, many were involved in ongoing collaborative studies (e.g., ELITE, GAMES, Gene SMART, GENESIS, and POWERGENE). A consensus emerged among participants that it would be advantageous to bring together all current studies and those recently launched into one new large collaborative initiative, which was subsequently named the Athlome Project Consortium.


Subject(s)
Athletic Performance , Biomarkers/metabolism , Genomics/methods , Animals , Epigenesis, Genetic , Europe , Humans , Tissue Banks
6.
Br J Sports Med ; 49(23): 1486-91, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26582191

ABSTRACT

The general consensus among sport and exercise genetics researchers is that genetic tests have no role to play in talent identification or the individualised prescription of training to maximise performance. Despite the lack of evidence, recent years have witnessed the rise of an emerging market of direct-to-consumer marketing (DTC) tests that claim to be able to identify children's athletic talents. Targeted consumers include mainly coaches and parents. There is concern among the scientific community that the current level of knowledge is being misrepresented for commercial purposes. There remains a lack of universally accepted guidelines and legislation for DTC testing in relation to all forms of genetic testing and not just for talent identification. There is concern over the lack of clarity of information over which specific genes or variants are being tested and the almost universal lack of appropriate genetic counselling for the interpretation of the genetic data to consumers. Furthermore independent studies have identified issues relating to quality control by DTC laboratories with different results being reported from samples from the same individual. Consequently, in the current state of knowledge, no child or young athlete should be exposed to DTC genetic testing to define or alter training or for talent identification aimed at selecting gifted children or adolescents. Large scale collaborative projects, may help to develop a stronger scientific foundation on these issues in the future.


Subject(s)
Aptitude/physiology , Athletic Performance/physiology , Direct-To-Consumer Screening and Testing/standards , Genetic Testing/standards , Aptitude/ethics , Consensus , Deception , Direct-To-Consumer Screening and Testing/ethics , Direct-To-Consumer Screening and Testing/legislation & jurisprudence , Evidence-Based Medicine , Genetic Testing/ethics , Genetic Testing/legislation & jurisprudence , Genomics , Humans , Sports Medicine/ethics , Sports Medicine/legislation & jurisprudence , Sports Medicine/standards
7.
Adv Genet ; 84: 123-49, 2013.
Article in English | MEDLINE | ID: mdl-24262098

ABSTRACT

Numerous reports of genetic associations with performance- and injury-related phenotypes have been published over the past three decades; these studies have employed primarily the candidate gene approach to identify genes that associate with elite performance or with variation in performance-and/or injury-related traits. Although generally with small effect sizes and heavily prone to type I statistic error, the number of candidate genetic variants that can potentially explain elite athletic status, injury predisposition, or indeed response to training will be much higher than that examined by numerous biotechnology companies. Priority should therefore be given to applying whole genome technology to sufficiently large study cohorts of world-class athletes with adequately measured phenotypes where it is possible to increase statistical power. Some of the elite athlete cohorts described in the literature might suffice, and collectively, these cohorts could be used for replication purposes. Genome-wide association studies are ongoing in some of these cohorts (i.e., Genathlete, Russian, Spanish, Japanese, United States, and Jamaican cohorts), and preliminary findings include the identification of one single nucleotide polymorphism (SNP; among more than a million SNPs analyzed) that associates with sprint performance in Japanese, American (i.e., African American), and Jamaican cohorts with a combined effect size of ~2.6 (P-value <5×10(-7)) and good concordance with endurance performance between select cohorts. Further replications of these signals in independent cohorts will be required, and any replicated SNPs will be taken forward for fine-mapping/targeted resequencing and functional studies to uncover the underlying biological mechanisms. Only after this lengthy and costly process will the true potential of genetic testing in sport be determined.


Subject(s)
Athletes , Genetic Testing , Polymorphism, Single Nucleotide , Actinin/genetics , Athletic Performance , Genome-Wide Association Study , Humans , Peptidyl-Dipeptidase A/genetics , Running
8.
Physiol Rep ; 1(7): e00188, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24744865

ABSTRACT

The aim of this study was to elucidate the relative contribution of genes and environment on individual differences in motor control and acquisition of a force control task, in view of recent association studies showing that several candidate polymorphisms may have an effect on them. Forty-four healthy female twins performed brisk isometric abductions with their right thumb. Force was recorded by a transducer and fed back to the subject on a computer screen. The task was to place the tracing of the peak force in a force window defined between 30% and 40% of the subject's maximum force, as determined beforehand. The initial level of proficiency was defined as the number of attempts reaching the force window criterion within the first 100 trials. The difference between the number of successful trials within the last and the first 100 trials was taken as a measure of motor learning. For motor control, defined by the initial level of proficiency, the intrapair differences in monozygotic (MZ) and dizygotic (DZ) twins were 6.8 ± 7.8 and 13.8 ± 8.4, and the intrapair correlations 0.77 and 0.39, respectively. Heritability was estimated at 0.68. Likewise for motor learning intrapair differences in the increment of the number of successful trials in MZ and DZ twins were 5.4 ± 5.2 and 12.8 ± 7, and the intrapair correlations 0.58 and 0.19. Heritability reached 0.70. The present findings suggest that heredity accounts for a major part of existing differences in motor control and motor learning, but uncertainty remains which gene polymorphisms may be responsible.

9.
J Physiol ; 589(Pt 2): 297-306, 2011 Jan 15.
Article in English | MEDLINE | ID: mdl-21098007

ABSTRACT

Brain plasticity refers to changes in the organization of the brain as a result of different environmental stimuli. The aim of this study was to assess the genetic variation of brain plasticity, by comparing intrapair differences between monozygotic (MZ) and dizygotic (DZ) twins. Plasticity was examined by a paired associative stimulation (PAS) in 32 healthy female twins (9 MZ and 7 DZ pairs, aged 22.6±2.7 and 23.8±3.6 years, respectively). Stimulation consisted of low frequency repetitive application of single afferent electric stimuli, delivered to the right median nerve, paired with a single pulse transcranial magnetic stimulation (TMS) for activation of the abductor pollicis brevis muscle (APB). Corticospinal excitability was monitored for 30 min following the intervention. PAS induced an increase in the amplitudes of the motor evoked potentials (MEP) in the resting APB, compared to baseline. Intrapair differences, after baseline normalization, in the MEP amplitudes measured at 25-30 min post-intervention, were almost double for DZ (1.25) in comparison to MZ (0.64) twins (P =0.036). The heritability estimate for brain plasticity was found to be 0.68. This finding implicates that genetic factors may contribute significantly to interindividual variability in plasticity paradigms. Genetic factors may be important in adaptive brain reorganization involved in motor learning and rehabilitation from brain injury.


Subject(s)
Evoked Potentials, Motor/genetics , Motor Cortex/physiology , Neuronal Plasticity/genetics , Adult , Analysis of Variance , Brain-Derived Neurotrophic Factor/genetics , Electric Stimulation , Electromyography , Female , Genotype , Humans , Median Nerve/physiology , Surveys and Questionnaires , Transcranial Magnetic Stimulation
10.
Med Sci Sports Exerc ; 36(2): 233-40, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14767245

ABSTRACT

PURPOSE: The aim of this study was to assess the relative power of genetic and environmental contribution to the variation observed in neuromuscular coordination. METHODS: Using the twin model and comparing intrapair differences between monozygotic (MZ) and dizygotic (DZ) twins, we derived heritability estimates (h2). Forty healthy male twins, 10 MZ and 10 DZ pairs, aged 21.5 +/- 2.4 and 21 +/- 2.1 yr, respectively, performed a series of elbow flexions in one degree of freedom with different velocities attempting to accurately reach a target. Neuromuscular coordination was evaluated for both accuracy and economy of movement and assessed by kinematics and EMG activity. RESULTS: The heritability in movement accuracy as assessed by the displacement from the target at 70% maximal velocity was 0.87. The accuracy at 30% and 50% of maximal velocity showed that the intrapair variation of MZ twins did not differ significantly from that of DZ twins. High heritability indexes of 0.85 and 0.73 were found for neuromuscular coordination as expressed by movement economy, assessed by the relative EMG activity of biceps long head at 70% and 50% of maximal velocity; no genetic dependence was found for low velocities. CONCLUSION: In this study, heredity accounted for most of the existing differences in neuromuscular coordination in fast movements. This implies that movement strategies, which are organized in the CNS and control fast movements, are also strongly genetically dependent.


Subject(s)
Elbow/physiology , Movement/physiology , Muscle, Skeletal/physiology , Neuromuscular Junction/genetics , Neuromuscular Junction/physiology , Adult , Biomechanical Phenomena , Electromyography , Environment , Humans , Male , Task Performance and Analysis , Twins, Dizygotic , Twins, Monozygotic
11.
Eur J Appl Physiol ; 89(3-4): 309-18, 2003 May.
Article in English | MEDLINE | ID: mdl-12736839

ABSTRACT

Nine male pairs of monozygotic twins aged 11-14 years, height 147 (7.6) cm and body mass 39.7 (9.6) kg, participated in this study. Twin zygocity was tested using morphological, dermatoglyphic and hematologic methods, and Tanner's five stages were used for the evaluation of biological maturation. One twin from each pair undertook training for 6 months, three times a week, with running at 85-120% of the lactate anaerobic threshold (LT). Anthropometrics, determination of maximum O(2) uptake (.VO(2max)), LT and maximal blood lactate concentration ([La](max)) was carried out before, during and after training. No significant difference existed between the trained twins and their untrained brothers before training. After training, the trained twins increased their .VO(2max), (per kg body mass) by 10.6% and their LT by 18.2% (P<0.01), reaching values that differed significantly from those of their untrained brothers [57.5 (3.6) ml.kg(-1).min(-1) vs 55.4 (3.3) ml.kg(-1).min(-1) and 13.4 (1.1) km.h(-1) vs 12.7 (1.1) km.h(-1), respectively]. In addition, in the trained twins relative body fat was reduced (P<0.05) from 17.8 to 16.2% and their somatotype altered significantly (decrease of endomorphy and mesomorphy and increase of ectomorphy), while in the untrained twins there was no change in these parameters. Both groups of twins significantly increased their absolute .VO(2max) after the 6 months of training, the trained by 14,9% [from 2.08 (0.43) to 2.37 (0.45) l.min(-1)] and the untrained by 10.5% [from 2.10 (0.41) to 2.32 (0.47) l.min(-1)], but no difference was registered between them. A comparison of the intrapair changes in .VO(2max) of prepubertal and pubertal twins showed an influence of training in the prepubertal (19.3% vs 5.2%) but not in the pubertal twins (12.7% vs 13.1%). Using analysis of variance, the relative importance of training, heredity and their interaction was evaluated to be 20%, 70% and 10%, respectively, for the change in body fat, 35%, 45% and 20%, respectively, for the change in relative .VO(2max) and 25-30%, 50-60% and 15-20%, respectively, for the change in LT. In conclusion, training during pubertal growth can favour aerobic power (depending on body composition) as well as aerobic capacity, but it has no effect on absolute .VO(2max). Genetic control seems to have a strong effect on the extent of adaptations, and the genotype-training interaction explains a small, but prominent part of them.


Subject(s)
Anaerobic Threshold/physiology , Exercise/physiology , Lactic Acid/blood , Oxygen Consumption/physiology , Physical Education and Training/methods , Puberty/physiology , Twins, Monozygotic , Adaptation, Physiological/physiology , Adolescent , Age Factors , Aging/physiology , Body Mass Index , Child , Exercise Test , Humans , Male , Statistics as Topic
SELECTION OF CITATIONS
SEARCH DETAIL
...