SEARCH · Search PubMed

Results for “polygenicity”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

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

At least 991 records · Page 55Linked to original sources

PubMed2004

[Analysis of the expression system of gene radius incompletes in Drosophila melanogaster].

The genetic expression system of gene radius incompletes was studied by substituting regions of chromosome 3 from line th st sr ca, which has drastically reduced ri expression, to regions of chromosome 3 from a "selection" line ri s having very high expression of this gene. Virtually all chromosome 3 was shown to carry polygenes controlling phenotypic expression of oligogenic mutation ri. Chromosome regions making large (as well as small and even negative) contributions to sizes of the distal and proximal fragments of the latitudinal wing vein were found. These results suggest that the genetic system of expression does not correspond to the generally accepted postulates of K. Mather on equal, small, and additive contributions of polygenes.

Animals↗

PubMed2002

Genetics and bone. Using the mouse to understand man.

The rationale for use of inbred strains of mice in bone research is well recognized and includes: a) practical factors (economics of scale, rapid development of adult status, pre-existing knowledge, down-sized technologies) and b) proven methodologies for genetic studies (polygenic trait analyses, mapping tools, genomic sequencing, methods for gene manipulation). Initial investigations of inbred strains of mice showed that femoral and lumbar vertebral volumetric bone mineral density (BMD, mg/mm(3)) by pQCT varied in excess of 50% for femurs and 9% in vertebral BMD. Two strains - low BMD C57BL/6J (B6) mice and high BMD C3H/HeJ (C3H) - were investigated for insights to their BMD diversity. B6C3F2 females derived from intercrossing B6C3F1s were raised to adult skeletal status at 4 months, then necropsied for phenotyping of bone and genotyping of genomic DNA. 1000 F2 females were genotyped for PCR product polymorphisms on all 19 autosomes at approximately 15 cM. Genome wide analyses for genotype-phenotype correlations showed 10 chromosomes (Chrs) carried genes for femoral and 7 Chrs for vertebral BMD. LOD scores ranged from 2.90 to 24.4, and percent of F2 variance accounted for ranged from 1 to 10%. Analyses of main effects revealed both dominant-recessive and additive inheritance patterns. Both progenitor strains carried alleles with positive and negative effects on BMD of each bone sites. A remarkable array of additonal skeletal phenotypes (femur and vertebral geometry, strength measures, serum markers) also proved polygenic in nature, with complex segregation patterns. Verification of BMD quantitative trait loci (QTLs) was undertaken by creating congenic B6 strains carrying individual QTL regions from C3H. Following 6 cycles of backcrossing a QTL-containing region from C3H to the B6 strain, N6F2 congenic strain mice were aged to 4 months, then genotyped for the QTL region and phenotyped for skeletal traits. Comparison of mice homozygous for C3H alleles versus homozygous for B6 alleles in the QTL regions showed that femoral BMD increased or decreased significantly in congenic strains, as was predicted from F2 data. Gender differences specific to BMD QTLs have been revealed, as have more than 30 additional phenotypes associated with cortical and trabecular structural parameters and biomechanical properties.

Journal Article↗

PubMed2005

Genetic basis of hybrid male sterility among three closely related species of Drosophila.

The genetic basis of hybrid male sterility among three closely related species, Drosophila bipectinata, D. parabipectinata and D. malerkotliana has been investigated by using backcross analysis methods. The role of Y chromosome, major hybrid sterility (MHS) genes (genetic factors) and cytoplasm (non-genetic factor) have been studied in the hybrids of these three species. In the species pair, bipectinata--parabipectinata, Y chromosome introgression of parabipectinata in the genomic background of bipectinata and the reciprocal Y chromosome introgression were unsuccessful as all males in second backcross generation were sterile. Neither MHS genes nor cytoplasm was found important for sterility. This suggests the involvement of X-Y, X-autosomes or polygenic interactions in hybrid male sterility. In bipectinata--malerkotliana and parabipectinata--malerkotliana species pairs, Y chromosome substitution in reciprocal crosses did not affect male fertility. Backcross analyses also show no involvement of MHS genes or cytoplasm in hybrid male sterility in these two species pairs. Therefore, X- autosome interaction or polygenic interaction is supposed to be involved in hybrid male sterility in these two species pairs. These findings also provide evidence that even in closely related species, genetic interactions underlying hybrid male sterility may vary.

Animals↗

PubMed2005

[Statistical parameter "essentiality of heterosis" and its genetic meaning].

An additive dominant model of inheritance of a quantitative trait in a group of hybrids is considered. The parameter "essentiality of heterosis," associated with the frequency of high-parent heterosis, was proposed to characterize the expression of a trait in a group. An expression was obtained to relate essentiality of heterosis, mean dominance, and trait polygenity, which is fulfilled upon a random and independent distribution of advantageous alleles among the parents. A measure of polygenity of a trait taking into account inequality of quantitative effects of different loci was proposed.

Crosses, Genetic↗

PubMed2005

Bioinformatics meets clinical informatics.

The field of bioinformatics has exploded over the past decade. Hopes have run high for the impact on preventive, diagnostic, and therapeutic capabilities of genomics and proteomics. As time has progressed, so has our understanding of this field. Although the mapping of the human genome will certainly have an impact on health care, it is a complex web to unweave. Addressing simpler "Single Nucleotide Polymorphisms" (SNPs) is not new, however, the complexity and importance of polygenic disorders and the greater role of the far more complex field of proteomics has become more clear. Proteomics operates much closer to the actual cellular level of human structure and proteins are very sensitive markers of health. Because the proteome, however, is so much more complex than the genome, and changes with time and environmental factors, mapping it and using the data in direct care delivery is even harder than for the genome. For these reasons of complexity, the expected utopia of a single gene chip or protein chip capable of analyzing an individual's genetic make-up and producing a cornucopia of useful diagnostic information appears still a distant hope. When, and if, this happens, perhaps a genetic profile of each individual will be stored with their medical record; however, in the mean time, this type of information is unlikely to prove highly useful on a broad scale. To address the more complex "polygenic" diseases and those related to protein variations, other tools will be developed in the shorter term. "Top-down" analysis of populations and diseases is likely to produce earlier wins in this area. Detailed computer-generated models will map a wide array of human and environmental factors that indicate the presence of a disease or the relative impact of a particular treatment. These models may point to an underlying genomic or proteomic cause, for which genomic or proteomic testing or therapies could then be applied for confirmation and/or treatment. These types of diagnostic and therapeutic requirements are most likely to be introduced into clinical practice through traditional forms of clinical practice guidelines and clinical decision support tools. The opportunities created by bioinformatics are enormous, however, many challenges and a great deal of additional research lay ahead before this research bears fruit widely at the care delivery level.

Computational Biology↗

PubMed2005

A contribution to genetic etiology of complex regional pain syndrome type I (algodystropy syndrome) based on quantitative analysis of digitopalmar dermatoglyphics in sixty men.

The patterns of the ridges of the skin of the fingers and palms were determined in sixty men with complex regional pain syndrome (type I) as a measure of disease prevention. The study included 25 dermatoglyphic traits: number of epidermal ridges on all ten fingers; their sum for five and ten fingers; four traits on both palms, i.e. between a-b, b-c and c-d triradii; atd angles: and their bilateral sum. The data obtained were compared with those recorded in a control group of 200 pairs of imprints of phenotipycally healthy male adults from the Zagreb area. Statistically significant difference from control values were found in 12 dermatoglyphic variables, including an increased sum of ridges on nine fingers (except for left second finger pad), and total sum for five and ten fingers. These findings suggested the polygenic system responsible for development of dermatoglyphics to be identical with some polygenic loci for the onset of algodystrophy syndrome, which might prove useful in disease prevention (e.g., taking fingerprints following a trauma and before rehabilitation), and to facilitate identification of risk groups, and thus the treatment for this longterm and yet obscure syndrome.

Dermatoglyphics↗

PubMed1991

Body weight and longevity in genetically obese and non-obese mice fed fat-modified diets.

Polygenically obese and genetically related non-obese male mice were fed ad libitum purified diets differing in quantity or type of fat from weaning onward to determine effects upon weight gain and life span. Non-obese mice lived 71% longer than mice in the obese line (mean = 753 d versus 441 d). Obese mice fed a low-fat diet containing 1% corn oil by weight lived 26% longer than their obese counterparts fed high fat diets containing 20% additional fat as either corn oil or beef tallow. The low fat diet had more of a normalizing effect upon longevity than upon body weight in polygenically obese mice. Conversely, dietary fat concentration had little effect upon longevity in non-obese mice and more effect upon body weight than in genetically obese mice. Type of dietary fat had little effect upon body weight and no effect upon longevity. The results of this study suggest that life span was only partially explained by body weight, and furthermore, that genetics play a greater role than body weight or dietary fat concentration in determining life span.

Animals↗

PubMed1991

Inheritance of extreme overweight in black families.

We used complex segregation analysis to compare the genetic transmission of overweight in randomly selected black (N = 60) and white (N = 961) families. In both groups we found evidence for polygenic transmission. Major gene inheritance was strongly supported in whites and was marginally supported in blacks. Parameter estimates for black and white families were similar, suggesting that overweight is similarly transmitted in the black and white families we observed. There was evidence in both black and white families for high gene frequency and recessive gene expression. Extreme phenotypes common in black families may be the result of interactions between major genotype and polygenic or environmental factors; alternative explanations for differences in black and white families' transmission patterns are discussed. Replication with a larger group of black families is needed to confirm our findings.

Adolescent↗

PubMed1990

Genetics of acute inflammation: inflammatory reactions in inbred lines of mice and in their interline crosses.

Acute inflammation is induced by the subcutaneous injection of swollen polyacrylamide microbeads, its intensity measured by the cell and protein concentration of the local exudates. A large and continuous range of responses is obtained in different inbred strains of mice, which suggests a polygenic control of the inflammatory response. The variable levels of the global dominance observed in F1 hybrids issued from several parental combinations indicated that the pattern of alleles controlling high or low response was different in each parental strain. Balanced intercrossing of the 8 inbred strains studied has provided a genetically heterogeneous F3 population, presenting a high variability of responses. The value of the genetic part of F3 phenotypic variance, the spread of the interstrain differences, as well as the polygenic nature of the regulation of inflammatory responses pointed out the possibility to perform a bidirectional genetic selection by using the F3 mice as the foundation population, and response to microbeads as the selective phenotypic character.

Acrylic Resins↗

PubMedDate not supplied

[The effect of psyllium plantago in slightly to moderately hypercholesterolemic patients].

The hypocholesterolemic effect of psyllium plantago (PP) was evaluated in 14 individuals with polygenic hypercholesterolemia. Subjects with secondary dyslipidemias were excluded. Since their admission until the end of the study all the patients had to follow an isocaloric diet, with less than 10% of the calories provided as saturated fats, P/S relation greater than 1 and daily intake of less than 300 mgr of cholesterol. The study was divided in two stages; the first one, from week -6 to 0 evaluated exclusively the response to diet, and the stage II, from week 0 to +12, evaluated the response to PP. The PP in envelopes with 3.4 grs each, was taken dissolved in water three times daily before meals. In the weeks -6, 0, +4, +8 and +12 were done lipid profiles that included; total cholesterol, triglycerides, and high density cholesterol. Cholesterol of the low density lipoproteins was obtained with the formula of Friedewald modified by De Long. The use of PP produced at week 12 a reduction of 8% in total cholesterol and 11% in LDL cholesterol. With non significant changes in triglycerides and HDL-C. We conclude that PP can be used as a complement of diet in the management of polygenic hypercholesterolemia.

Adult↗

PubMed1979

Polymorphism of apolipoprotein E. II. Genetics of hyperlipoproteinemia type III.

Apolipoprotein E from human serum shows a genetic polymorphism determined by two autosomal codominant alleles, Apo En and Apo Ed. Homozygosity for the gene Apo Ed (phenotype Apo E-D) results in primary dysbetalipoproteinemia, but only some individuals with this phenotype develop gross hyperlipidemia (hyperlipoproteinemia type III). Vertical transmission of dysbetalipoproteinemia represents pseudodominance due to the high frequency of the gene Apo Ed. Dysbetalipoproteinemia is already expressed in childhood. To assess the influence of other genes on the expression of hyperlipidemia in phenotype Apo E-D, comparative studies were carried out in kindreds of hypercholesterolemic (group A) and normo- or hypocholesterolemic probands with dysbetalipoproteinemia (group B). This demonstrated the occurrence of familial (non-type III) forms of hyperlipidemia in group A but not in group B kindreds. Distribution of lipoprotein phenotypes in five of the group A kindreds was consistent with the occurrence of familial combined hyperlipidemia. Apo E phenotypes and hyperlipidemia segregated independently. It is concluded that primary dysbetalipoproteinemia is a frequent monogenic variant of lipoprotein metabolism, but not a disease. Coincidence in one individual of genes for this specific dyslipoproteinemia with any of the genes for monogenic or polygenic forms of familial hyperlipidemia results in hyperlipoproteinemia type III. Hence hyperlipoproteinemia type III is caused by at least two non-allelic genes and is a polygenic disorder.

Adolescent↗

PubMed1990

[A concept of limiting genetic factors of expression, organization, and evolution].

Elicitation and analysis of limiting genetic factors represent convenient method for approximate description of complex molecular-genetic systems. In sequential metabolic ways, the limiting is based on the minimum of catalytic activity, in parallel ones--on the maximum activity. In polygenic systems, the expressing polygenes affect always the limiting oligogenes. Limiting genes are only available to selection on the population level, the non-limiting genes being neutrally evolving. This result eliminates the acuteness of the Haldane's dilemma. The complex genetic systems could be quickly evolving by relay-race principle with sequentional change of limiting genes and without violation of Haldane's dilemma. The limiting factors of organization which restrict the possibilities of some special evolutionary directions have the key role in evolution. These limits were historically overcome by acceptance of evolutionary acquirements of wide usage. The sequence of such limits and acquirements was assumed as a basis of "scenario" of Prebiological and Biological Molecular Evolution. The concept is illustrated by some examples and results of theoretical analysis.

Animals↗

PubMed1990

Common major gene inheritance of extreme overweight.

We studied 3925 individuals in 961 families to determine the mode of inheritance of overweight. As an index of overweight, we examined body mass index. Our analyses indicate that the most likely genetic model for susceptibility to overweight included moderate polygenic inheritance (34% of variance resulting from many genes with small effects) and common (21% frequency) recessively expressed major genes (a few genes with large effects on the individuals who possess them). Standard statistical criteria for accepting both polygenic and major gene inheritance were met, including tests of Mendelian transmission. These results suggest that recessive major gene inheritance of overweight may be common and that homozygosity for overweight susceptibility alleles often results in overweight. Clinical, biologic, and empirical observations all suggest genetic heterogeneity, that is, more than one predisposing gene.

Adult↗

PubMed1985

The genetics of panic disorder and agoraphobia.

Panic disorder, comprising also agoraphobia for the purpose of this review, has a prevalence of 1.2-8.4 per cent, affecting females twice as frequently as males, and has a mean age of onset of 25. It is one of the more familial diseases in Psychiatry in that 2/3 of cases have relatives affected with the same condition, and the risk to first degree relatives is approximately 3-4 times the rate of the general population. Although some family studies have suggested an overlap in the transmission of panic disorders and depression, and a common diathesis hypothesis has been proposed, depression is more common in the families of depressives, as in panic disorder in the families of probands with panic disorder. Twin studies of anxiety disorders, although limited in number, report a 30-40 per cent concordance among MZ twins, against 0-4 per cent among DZ twins, which supports a genetic predisposition. The mode of transmission is uncertain. Studies which have used the 'ancestral pairs' method (which examines the incidence of the condition in maternal versus paternal forebears, on the assumption that single locus transmission is favored by unilateral clustering, and polygenic theories are favored by a more even spread) have favored single locus transmission, although such unilateral clustering can still be accommodated within a multifactorial-polygenic hypothesis. Potential biological markers for the condition are reviewed. The observation that lactate infusion can precipitate panic attacks in predisposed individuals is well established. The association with mitral valve prolapse suggests that perhaps 38 per cent of patients presenting with symptoms of panic disorders have mitral valve prolapse on echocardiography. The possibility of an endogenous anxiety-producing agent that binds to the benzodiazepine receptor is discussed.

Adolescent↗

PubMed1986

Hereditary factors in Takayasu disease. II. Various blood types.

As HLA studies suggest that the genetic factors contributing to the pathogenesis of Takayasu disease may be polygene, various red blood types, allotypes of serum protein and red blood cell enzyme polymorphisms in eighty-four patients with Takayasu disease were studied and their phenotypes and gene frequencies were compared with those in healthy Japanese. Statistically significant high frequencies of phenotypes and/or gene frequencies were confirmed in MNSs, Rh-Hr, Tf, Gc and Pi in Takayasu disease, as compared with those in controls. These characteristics of gene frequencies were more remarkable in patients who do not carry HLA Bw52. These data suggest that the genetic factors contributing to the pathogenesis of Takayasu disease are polygene and may be located in chromosome No. 1, 4 and 14.

Adult↗

PubMed1988

Hypertension and sodium-lithium countertransport in Utah pedigrees: evidence for major-locus inheritance.

Likelihood analysis was used to test for evidence that an allele at a major locus elevates rates of sodium-lithium countertransport (SLC) in a sample of 1,989 members of 89 Utah pedigrees. The pedigrees were ascertained through two or three sibs who died of stroke before age 74 years (stroke pedigrees), through hypertensive and normotensive probands of the Salt Lake Center of the Hypertension Detection and Followup Program (HDFP pedigrees), or through men who suffered a myocardial infarction before age 55 years (coronary pedigrees). Major-locus inheritance could be rejected in the total sample; transmission probability estimates of tau1 = .972, tau2 = .520, tau3 = .185 differed significantly from Mendelian transmission specified by tau1 = 1, tau2 = 1/2, tau3 = 0. However, heterogeneity between ascertainment groups was significant (chi2(18) = 40.06, P less than .01) and justified analysis within subsets of the sample. In the stroke pedigrees, evidence of major-locus inheritance was not found; polygenic heritability was estimated as .647. In the HDFP pedigrees, estimates of tau1 = .987, tau2 = .430, tau3 = .506 differed significantly from Mendelian transmission; the inferred model consisted of a mixture of two distributions incompatible with both Mendelian and environmental transmission but compatible with polygenic inheritance within distributions. In the coronary pedigrees, the hypothesis of Mendelian transmission could not be rejected. In the coronary pedigrees, the evidence supported an incompletely recessive allele with a frequency of .227 which elevated the level of SLC to a mean of .530 mmol/liter RBC/h.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1988

Pedigree analysis of HDL cholesterol concentration in baboons on two diets.

Using complex segregation analysis, we examined the effects of genetic factors and diet on serum concentrations of high-density-lipoprotein cholesterol (HDL-C) in baboons. In analyses of 710 baboons in 23 sire families, we found evidence for a major gene as well as a polygenic contribution to HDL-C concentration in baboons fed a basal (chow) diet and also in the same animals after challenge with a high-cholesterol, saturated-fat diet. There was evidence for a polygenic contribution to the change in HDL-C concentration in response to the dietary challenge, but there was no evidence for a major gene effect.

Animals↗

PubMed1988

Genetic analysis of systemic lupus erythematosus: 1. Detection of disease-associated variant proteins by two-dimensional gel electrophoresis.

Various genetic studies indicate that development of systemic lupus erythematosus (SLE) is regulated by the mode of multifactorial inheritance, i.e., by the overall effect of polygenes and environmental factors. To elucidate some variant genes involved in the polygenic system responsible for onset of SLE, we resolved and measured the protein components of lymphocytes and sera from inactive-SLE patients, their relatives, and normal controls, using two-dimensional gel electrophoresis. Intercomparison of polypeptide patterns between patients and controls revealed three major variations, two detected in lymphocytes and one in sera. These variations were present in 66-82% of the patients, in 20-36% of the control group, and in 41-64% of the relatives. In addition, nearly half of SLE patients, but only one of 19 normal controls, possessed all three SLE-associated traits, suggesting that these variant proteins may reflect in part the genetic factors contributing to development of SLE.

Adolescent↗