PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Genetic correlation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1989

Genetic correlations and maternal effect coefficients obtained from offspring-parent regression.

Additive genetic variances and covariances of quantitative characters are necessary to predict the evolutionary response of the mean phenotype vector in a population to natural or artificial selection. Standard formulas for estimating these parameters, from the resemblance between relatives in one or two characters at a time, are biased by natural selection on the parents and by maternal effects. We show how these biases can be removed using a multivariate analysis of offspring-parent regressions. A dynamic model of maternal effects demonstrates that, in addition to the phenotypic variance-covariance matrix of the characters, sufficient parameters for predicting the response of the mean phenotype vector to weak selection are the additive genetic variance-covariance matrix and a set of causal coefficients for maternal effects. These can be simultaneously estimated from offspring-parent regressions alone, in some cases just from the daughter-mother regressions, if all of the important selected and maternal characters have been measured and included in the analysis.

Analysis of Variance↗
PubMed2003

Born to be anxious: neuroendocrine and genetic correlates of trait anxiety in HAB rats.

This review summarises behavioural, neuroendocrine, and genetic characteristics of Wistar rats bred for either high (HAB) or low (LAB) anxiety-related behaviour. Compared to LABs, HAB animals show signs of extreme trait anxiety in a variety of behavioural tests; they further prefer passive coping strategies, indicative of a genetically linked depression-like behaviour, and show signs of increased stress vulnerability. All behavioural parameters associated with trait anxiety are robust and consistent. Resembling psychiatric patients, HAB rats respond to exposure to ethologically relevant stressors with a hyper-reactivity of the hypothalamic-pituitary-adrenal axis and show a pathological outcome of the combined dexamethasone/corticotropin-releasing hormone (Dex/CRH) challenge test. Experimental evidence indicates that over-expression and -release of vasopressin in the hypothalamic paraventricular nucleus is responsible for these behavioural and neuroendocrine phenomena, making the neuropeptide gene a candidate gene of trait anxiety/depression. Indeed, preliminary molecular genetic approaches succeeded in identifying polymorphisms in the promoter structure of the vasopressin gene. This may have implications for understanding the molecular basis for individual variations in trait anxiety and for psychopathology.

Animals↗
PubMed1975

[Heterogeneity and several clinico-genetic correlations in epilepsy under inbred conditions].

The types of inheritance and clinico-genetical correlatins of epilepsy in 291 probands in conditions of inbreeding were studied. The data obtained confirmed the multifactorial (gene-polygene+medium) inheritance of epileptic and convulsive predispositions and contradicted the hypothesis of primarily recessive inheritance of epilepsy. Together with family forms of the disease, which were communicated mainly according to an uncertained and dominant type (rarely recessive type), there were existed forms of eipilepsy with incomplete genetical hereditary predisposition (which were observed in relatives of 2-3 generations only by epileptic features) and phenotypical forms concentrated in sporadic groups. There were found the dependences onthe rate of occurrence of secondary epilepsy (with or without epileptoidness), epileptoid psychopathy and children convulsions in relatives, on the type of inheritance, the age of manifestations, the form, polymorphism of the attacks, the severity of the developement of epilepsy, the expressiveness of epileptoidness in probands and high severity of the disease with distinct epileptoidness inbreeding families. The hereditary heterogeneity of epilepsy, associated, perhaps, with pleiotropy of epileptic (with or without epileptoidness) genes, was assumed. The found clinico-genetical correlaltions mightbe taken into account in medico-genetical prognosis of families burdened by epilspsy in analogous populational-demographic conditions.

Adolescent↗
PubMed1974

Genetic correlation of a mouse light chain variable region marker with a thymocyte surface antigen.

The inbred and congenic strain distribution of the I(H)-peptide marker in the variable region of mouse immunoglobulin light chains has been compared with other known genetic markers. A positive correlation was noted between the I(H)-peptide marker and expression of the Ly-3.1 thymocyte cell surface antigen. This suggests that the locus responsible for I(H)-peptide expression is genetically linked to the Ly-2 and Ly-3 loci in linkage group XI on chromsome 6 of the mouse.

Animals↗
PubMed2025

Is there a genetic correlation between tinnitus and temporomandibular joint disorder?: A two-sample Mendelian randomization study.

Tinnitus and temporomandibular disorder (TMD) are frequent coexistence of clinical symptoms caused by some systemic diseases in all humans. The observational research results on the correlation between tinnitus and TMD are inconsistent with the reported findings. The purpose of the study was to explore the bidirectional causal relationship between tinnitus and TMD. This study adopts a two-sample Mendelian randomization (MR) methodology. Single-nucleotide polymorphisms from the genome-wide association study were used as instrumental variables to elucidate the bidirectional causal relationship between tinnitus and TMD. The quality of our study was evaluated in accordance with the STROBE-MR guidelines. The MR analysis results showed that tinnitus (yes, most or all of the time now) could be significantly reduced TMD muscular pain linked with fibromyalgia (OR = 0.239, 95% CI: 0.087-0.66, P = .0057), but there was no correlation between other frequencies of tinnitus and the increased risk of TMD in genetic predisposition (all P > .05). The reverse MR analysis revealed no causal relationship and correlation between TMD exposure and increased risk of tinnitus. Sensitivity analysis indicated no horizontal pleiotropy and insignificant heterogeneity. This MR study supports evidence of a correlation between high-frequency tinnitus and reduced risk of TMD muscle pain associated with fibromyalgia. Further research on disease mechanisms are needed to explore the correlation between tinnitus and TMD.

Humans↗
PubMed1994

[Myotonic dystrophy: study of clinico-genetic correlation in a pair of relatives (father-son)].

We report the case of a child with myotonic dystrophy (DM) with symptoms beginning at the age of seven, whose genetic study showed an additional DNA fragment, greater than of his father, an asymptomatic carrier. The clinical and molecular analysis of this parent-child pair are probably the first described in Brazil, since the recent discovery of genetic abnormality in DM by American and European researchers, that explained the long-debated phenomenon of "anticipation" in this disease. The main advances in molecular genetics in DM and its correlation with increasing severity and earlier onset of the symptoms in successive generations of a family are commented briefly.

Child↗
PubMed2004

Longevity and metabolism in Drosophila melanogaster: genetic correlations between life span and age-specific metabolic rate in populations artificially selected for long life.

We measured age-specific metabolic rates in 2861 individual Drosophila melanogaster adult males to determine how genetic variation in metabolism is related to life span. Using recombinant inbred (RI) lines derived from populations artificially selected for long life, resting metabolic rates were measured at 5, 16, 29, and 47 days posteclosion, while life spans were measured in the same genotypes in mixed-sex population cages and in single-sex vials. We observed much heritable variation between lines in age-specific metabolic rates, evidence for genotype x age interaction, and moderate to large heritabilities at all ages except the youngest. Four traits exhibit evidence of coordinate genetic control: day 16 and day 29 metabolic rates, life span in population cages, and life span in vials. Quantitative trait loci (QTL) for those traits map to the same locations on three major chromosomes, and additive genetic effects are all positively correlated. In contrast, metabolic rates at the youngest and oldest ages are unrelated to metabolic rates at other ages and to survival. We suggest that artificial selection for long life via delayed reproduction also selects for increased metabolism at intermediate ages. Contrary to predictions of the "rate of living" theory, we find no evidence that metabolic rate varies inversely with survival, at the level of either line means or additive effects of QTL.

Aging↗
PubMed2005

Clinical and genetic correlates of serum aldosterone in the community: the Framingham Heart Study.

BACKGROUND: We investigated the environmental and genetic sources of interindividual variability in serum aldosterone level in a large, community-based sample. METHODS: We examined the relation of serum aldosterone to vascular risk factors, urine sodium, and candidate single nucleotide polymorphisms in 2891 Framingham Offspring Study participants (53.2% women, mean age 59 years) using multivariable linear regression. Multivariable logistic regression was used to identify predictors of high (top quartile) and low (lowest quartile) serum aldosterone values. We estimated heritability of serum aldosterone via variance-component methods and evaluated linkage via a 10-cM-density genome scan. RESULTS: Clinical variables related to higher serum aldosterone level included female sex, diuretic treatment, and a higher total/high density lipoprotein cholesterol ratio. A high urinary sodium excretion, postmenopausal status (without hormone replacement therapy), increased pulse pressure, and prevalent cardiovascular disease were related to lower serum aldosterone values. Urinary sodium was the strongest correlate of serum aldosterone (R2= 10%). Serum aldosterone levels did not differ by genotype in the aldosterone synthase (CYP11B2c.1-344C>T) and the mineralocorticoid receptor (NR3C2c.754A>G) genes. The estimated heritability of serum aldosterone was 0.10. No chromosomal region attained a log-of-the-odds score >1 in multipoint linkage analysis. CONCLUSIONS: We observed a complex relation between serum aldosterone and vascular risk factors. The genetic contribution to serum aldosterone level was modest.

Adult↗
PubMed1997

Antiperinuclear factor--clinical, serological and genetic correlates in Israeli patients with rheumatoid arthritis.

The possible association between the presence of antiperinuclear factor (APF) and clinical and genetic parameters was investigated in 54 Israeli patients with rheumatoid arthritis (RA). Rheumatoid factor (RF) was detected in the sera of 43 patients (80%) and APF was positive in 33 (61%). No significant statistical differences were found in the presence of HLA-DR4 and/or DR1 between APF-positive and -negative patients. Furthermore, neither the Ritchie articular index nor the patient's functional class correlated with the presence of APF. The results of our study suggested that although Israeli patients have a different genetic background, the presence and behaviour of APF is similar to that of other Caucasian populations.

Adult↗
PubMed2003

Genetic correlations between brain volumes and the WAIS-III dimensions of verbal comprehension, working memory, perceptual organization, and processing speed.

We recently showed that the correlation of gray and white matter volume with full scale IQ and the Working Memory dimension are completely mediated by common genetic factors (Posthuma et al., 2002). Here we examine whether the other WAIS III dimensions (Verbal Comprehension, Perceptual Organization, Processing Speed) are also related to gray and white matter volume, and whether any of the dimensions are related to cerebellar volume. Two overlapping samples provided 135 subjects from 60 extended twin families for whom both MRI scans and WAIS III data were available. All three brain volumes are related to Working Memory capacity (r = 0.27). This phenotypic correlation is completely due to a common underlying genetic factor. Processing Speed was genetically related to white matter volume (r(g) = 0.39). Perceptual Organization was both genetically (r(g) = 0.39) and environmentally (r(e) = -0.71) related to cerebellar volume. Verbal Comprehension was not related to any of the three brain volumes. It is concluded that brain volumes are genetically related to intelligence which suggests that genes that influence brain volume may also be important for intelligence. It is also noted however, that the direction of causation (i.e., do genes influence brain volume which in turn influences intelligence, or alternatively, do genes influence intelligence which in turn influences brain volume), or the presence or absence of pleiotropy has not been resolved yet.

Brain↗
PubMed2004

Fine-scale spatial genetic correlation analyses reveal strong female philopatry within a brush-tailed rock-wallaby colony in southeast Queensland.

We combine spatial data on home ranges of individuals and microsatellite markers to examine patterns of fine-scale spatial genetic structure and dispersal within a brush-tailed rock-wallaby (Petrogale penicillata) colony at Hurdle Creek Valley, Queensland. Brush-tailed rock-wallabies were once abundant and widespread throughout the rocky terrain of southeastern Australia; however, populations are nearly extinct in the south of their range and in decline elsewhere. We use pairwise relatedness measures and a recent multilocus spatial autocorrelation analysis to test the hypotheses that in this species, within-colony dispersal is male-biased and that female philopatry results in spatial clusters of related females within the colony. We provide clear evidence for strong female philopatry and male-biased dispersal within this rock-wallaby colony. There was a strong, significant negative correlation between pairwise relatedness and geographical distance of individual females along only 800 m of cliff line. Spatial genetic autocorrelation analyses showed significant positive correlation for females in close proximity to each other and revealed a genetic neighbourhood size of only 600 m for females. Our study is the first to report on the fine-scale spatial genetic structure within a rock-wallaby colony and we provide the first robust evidence for strong female philopatry and spatial clustering of related females within this taxon. We discuss the ecological and conservation implications of our findings for rock-wallabies, as well as the importance of fine-scale spatial genetic patterns in studies of dispersal behaviour.

Animals↗
PubMed1990

[A genetic correlational analysis of the behavioral and physiological characteristics of spontaneously hypertensive rats (SHR)].

The SHR rats differ from normotensive WKY rats in a number of behavioral and physiological traits. In order to determine causal or accidental nature of relationships between these traits and hypertension, their correlations with arterial pressure level in the 2nd generation of SHR x WKY hybrids (F2), were studied. A positive correlation of body mass and characteristics of potassium appetite with a level of blood pressure corresponding to interstrain differences between SHR and WKY rats was found in F2 population showing genetic connection of these traits with hypertension. The negative correlation in F2 between open-field activity and arterial pressure was opposite to interstrain differences and environmental correlation (within parental strains and F1 hybrids). It seemed to be caused by prevalence of environmental correlation or of accidental fixation of this trait in SHR strain over the genetic connection found in F2 hybrids.

Animals↗
PubMed2025

Interstrain Recombinants of Human Cytomegalovirus Reveal Complex Genetic Correlates and Epistasis Influencing Glycoprotein Display, Virion Infectivity and Spread Characteristics.

Most of the nucleotide diversity in the human cytomegalovirus (HCMV) genome is due to approximately 17 genes with 2-14 alleles each. These allelic genes are interspersed among longer stretches of highly conserved sequences with signatures of extensive recombination that would shuffle the allelic genes into a vast number of allelic haplotypes. Bacterial artificial chromosome clones derived from 3 independent clinical isolates (TB40/e (TB), TR and Merlin (ME)) display dramatic differences in the abundance of entry-mediating glycoproteins gH/gL/gO and gH/gL/UL128-131, virion infectivity and efficiency of cell-free and cell-to-cell modes of spread. Of these, TB and ME are the most phenotypically different and share only 2 of the 17 allelic genes. A set of recombinant HCMV was generated by coinfecting cells with TB and ME and restriction fragment length polymorphism (RFLP) analyses demonstrated complex crossover patterns. Most recombinants were either "TB-like" with much more gH/gL/gO than gH/gL/UL128-131, or "ME-like" with much more gH/gL/UL128-131. This correlated with a TB or ME UL128 sequence, consistent with a G/T polymorphism affecting UL128 pre-mRNA splicing. One recombinant had a gH/gL/gO:gH/gL/UL128-131 ratio of 0.8, suggesting genetic determinants beyond UL128. Virion infectivity correlated with TB versus ME-like glycoprotein display, but intragroup variability indicated additional factors and variability in spread efficiency and the contribution of cell-free and cell-to-cell spread modes indicated an influence of characteristics beyond virion infectivity. Results suggest that the relationships among these three phenotypes are not strictly causal and that all three phenotypes are genetically complex and influenced by epistasis among polymorphic loci across the genome.

Journal Article↗
PubMed2003

Evolvability and genetic constraint in Dalechampia blossoms: genetic correlations and conditional evolvability.

The short-term evolvability of a character is closely related to its level of additive genetic variation. However, a large component of the variation in any one character may be pleiotropically linked to other characters under the influence of different selective factors. Therefore, the organization of the organism into quasi-independent modules may be an important prerequisite for evolvability. In this paper we propose to study character evolvability in terms of conditional genetic variation. By estimating the amount of genetic variation in a character, y, that is independent of other characters, x, we can assess the evolvability of y when there is stabilizing selection on x. We suggest that systematic use of conditioning may help build a picture of modular organization and quasi-independent evolvability. As an illustration, we use this approach to assess the evolvability of floral characters in Dalechampia scandens (Euphorbiaceae). Although our study population had relatively low levels of genetic variation at the outset, we find evidence that conditioning may lead to substantial further reduction in the genetic variation available for independent adaptation. This provides additional evidence that the D. scandens blossom is constrained in its short-term evolvability.

Biological Evolution↗