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Results for “polymorphism, genetic”

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At least 19 recordsLinked to original sources
PubMed1979

Genetic polymorphism in normal human fibroblasts as analyzed by two-dimensional polyacrylamide gel electrophoresis.

Two dimensional gel electrophoresis has been used to measure the degree of genetic polymorphism among the proteins of normal human fibroblasts. Autoradiographic analysis of the gel protein profiles from radioactively labeled cells allowed comparison of as many as 300 discrete polypeptides at a time. In addition, a newly developed technique for double label autoradiography was used to increase the sensitivity of the system for detection of small differences in the protein profiles of different cell lines. Only about 1.2% of the proteins of different cell lines were found to differ in their electrophoretic mobility. This corresponds to an average heterozygosity of approximately 0.6%. Previous studies of genetic polymorphism using different methods of one-dimensional electrophoretic analysis have estimated the average heterozygosity of the human population at about 6.7%. Detailed mathematical analysis shows the variation of the observed from the expected number of differences to be statistically highly significant. While the reasons for this difference are not clear, the observation of low levels of genetic polymorphism on two-dimensional gels should enhance the usefulness of this technique for detection of altered proteins in inherited disease.

Adult↗
PubMed1979

Genetic polymorphisms and intrauterine development. Evidence of decreased heterozygosity in light-for-dates human newborn babies.

In 2 independent samples of low-birth-weight infants the proportion of females and homozygotes for a series of polymorphic systems was higher in light-for-dates than in preterm babies. The observation seems to give support to the hypothesis that homozygosity for 'normal' polymorphisms may decrease in general intrauterine growth rate. Since it is known that survival rate is strongly related to birth weight, a correlation between growth retardation and homozygosity may have a major role in the maintenance of such polimorphisms.

ABO Blood-Group System↗
PubMedDate not supplied

Immunoglobulin levels and genetic polymorphisms in the Sukuma of Tanzania.

In a sample of 150 Sukuma from north central Tanzania, immunoglobulin G, M, A, and E levels were studied in relation to the phenotypes in 22 polymorphic systems. No strong associations were detected, though there is a suggestion of an association between IgG and haptoglobin type, with elevation of mean levels in heterozygotes.

Blood Group Antigens↗
PubMed1978

Genetic polymorphism of human phosphoglycolate phosphatase (PGP).

1. A method has been devised for the detection after starch-gel electrophoresis of phosphoglycolate phosphatase (PGP) isozymes. 2. PGP isozymes can be detected in all human tissues including red cells, lymphocytes and cultured fibroblasts. The highest activities occur in skeletal muscle and cardiac muscle. 3. PGP is a relatively specific phosphatase which shows enhanced activity in the presence of mercaptoethanol at a neutral pH.4. Six different commonly occurring electrophoretic types of PGP have been identified. Family studies indicate that they are determined by three alleles at an autosomal locus (PGP). 5. The gene frequencies of PGP1, PGP2 and PGP3 in a random sample of Europeans were 0.826, 0.129 and 0.045 respectively. 6. The three-banded isozyme patterns seen in heterozygotes suggest that PGP is a dimeric enzyme.

Electrophoresis, Starch Gel↗
PubMedDate not supplied

[Modern concepts of the metabolism and genetic polymorphism of collagen (a review)].

The data on structure, biosynthesis, post-synthetic modifications, extracellular development and degradation of collagen are briefly reviewed. Role of main enzymes, participating in collagen turnover, is discussed. Isoforms of the protein are considered in details. The importance of studies on collagen proteins is noted in connection with investigations on morphogenesis, cell differentiation, regeneration.

Animals↗
PubMed1978

Genetic polymorphism of serum alpha-1-protease inhibitor (alpha-1-antitrypsin): Pi i, a deficient allele of the Pi system.

The microheterogeneity of the I allele of the Pi system of APi (alpha-1-antitrypsin) was studied in 43 individuals with the new PAGIF technique. The unique aspect of the I allele product (unequal distribution of bands 4 and 6), previously demonstrated with acid-starch gel, was confirmed. In addition, two subtypes of the Pi I allele--I1 and I2--were clearly distinguished. Serum concentrations of APi associated with the expression of the I allele were significantly decreased (68% of normal values) and thus very similar to those associated with the expression of the S allele. This indicates that the I allele can be considered as a "deficient" allele of the Pi system.

Alleles↗
PubMed1979

[Genetic polymorphism of erythrocytic enzymes in the Rennes area. Frequency of adenylate kinase, esterase D, adenosine deaminase, 6-phosphogluconate dehydrogenase, glutamate-pyruvate transaminase and glyoxyalase I phenotypes].

Blood donors from the Centre Régional de Transfusion Sanguine de Rennes were investigated for the phenotypic distribution of seven enzymatic systems : adenylate kinase, adenosine deaminase, esterase D, 6-phosphogluconate dehydrogenase, glutamate-pyruvate transaminase, phosphoglucomutase, and glyoxalase I. Two unusual phenotypes were observed: phenotype 6-1 for adenosine deaminase and phenotype 3-1 for transaminase GPT. For five of these enzymes, the statistical analysis points out significant differences in one or several of the European populations described in the literature.

Adenosine Deaminase↗
PubMed1979

Genetic polymorphism of the A subunit of human coagulation factor XIII.

Utilizing a fluorescent technique for the localization of transglutaminase activity after electrophoresis on thin layer agarose gels, we observed a new polymorphism of coagulation factor XIII in both platelets and plasma. The electrophoretic pattern was that of a dimeric protein. Homozygotes gave a single band, while heterozygotes presented a three banded pattern. The polymorphism was found to be due to variation of the A subunit. Data from Australian blood donors indicate that the A subunit of factor XIII has an autosomal locus.

Australia↗
PubMed1979

Genetic polymorphisms in diabetics and non-diabetics.

Phenotype distributions of some genetic polymorphisms are reported in a sample of 721 diabetics and 515 non-diabetic, non-blood donor controls. Reference is also made, in the case of the ABO and Rhesus systems, to previously published results for blood donors resident in the Durham area. Non-insulin-taking diabetics show an increased frequency of blood group A1 (and A1 + A2) when compared with controls. This difference is particularly marked in male diabetics. When diabetics are compared with age matched controls, the difference is confined to the older cases. It is proposed that this effect is predominantly the result of a deficiency of group A1 in controls rather than the result of increased susceptibility to the disease among A1 people. No association with any of the Rhesus phenotypes is shown. In non-diabetics, the results suggest an enhanced survival value for the rr genotype. No significant associations are seen when the MNSs, Kell, Lewis, Duffy, haptoglobin, red cell acid phosphatase, phosphoglucomutase, adenylate kinase, and adenosine deaminase distributions in these groups of subjects are compared.-

ABO Blood-Group System↗
PubMed2025

The role of candidate genetic polymorphisms in covid-19 susceptibility and outcomes.

BACKGROUND: This study aims to investigate the association between candidate host genetic polymorphisms and COVID-19 susceptibility, severity, hospitalization, hypoxia, and their combined effect, measured by the polygenic risk score (PRS). METHODS: Three hundred and seventy-six Lebanese participants, comprising 151 controls and 225 cases, were included. Clinical data were obtained from questionnaires and medical records. DNA isolated from peripheral blood was genotyped for ACE1 rs1799752, ACE2 rs2074192, TMPRSS2 rs75603675 and OAS1 rs107746771 using TaqMan assays, and for TMPRSS2 rs35074065 using Sanger Sequencing. Candidate genetic variants were analyzed in association with COVID-19 susceptibility, severity, hospitalization and hypoxia, using univariate and multivariate models. PRS constructed from the weighted sum of variants was evaluated in association with COVID-19 outcomes. RESULTS: In this study, there were no statistically significant differences in the frequencies of candidate variant alleles between cases, controls and within disease outcomes subgroups, after adjustment for confounders. PRS was not associated with COVID-19 susceptibility and hospitalization, it however significantly predicted COVID-19 severity (P = 0.01). CONCLUSION: This study highlights the importance of genetic testing for key host genes involved in COVID-19 life cycle and eventually measuring the PRS which proves to be an important tool for prognosis assessment in vulnerable individuals, potentially enhancing patient care.

Polymorphism, Genetic↗
PubMed2025

A comprehensive evaluation of candidate genetic polymorphisms in a large histologically characterized MASLD cohort using a novel framework.

BACKGROUND: There is a substantial heritable component to metabolic dysfunction-associated steatotic liver disease (MASLD), and several genetic variants that promote MASLD development or associate with its severity have been reported. These associations vary in terms of their effect size and degree of replication. METHODS: We developed a framework to classify previously identified MASLD genetic polymorphisms into 4 tiers based on effect size and extent of replication in the literature. We tested the association between "tier 1" single-nucleotide polymorphisms (OR ≥1.5, replicated in >2 independent studies) and biopsy measures of MASLD severity in a large, well-characterized histologic cohort of MASLD patients (n=3094). RESULTS: Across 19 "tier 1" variants reflecting 11 genetic loci, only those in the PNPLA3-SAMM50-PARVB locus showed significant associations with biopsy-proven fibrosis severity and NAFLD activity score; the highest risk was for the rs738409 p.I148M variant in PNPLA3. A genetic risk score based on "tier 1" variants, as well as a previously developed genetic risk score based on variants in PNPLA3, TM6SF2, and HSD17B13, were both associated with fibrosis and NAFLD activity score, but these results were driven entirely by PNPLA3 rs738409. CONCLUSIONS: Our study provides a framework to prioritize evaluation of genetic polymorphisms for future replication efforts and demonstrates that in a large case-only cohort, histologic severity of MASLD is only robustly associated with the presence of variation in PNPLA3 among known candidate genes. These findings may have implications for patient risk stratification based on the presence of PNPLA3 rs738409.

Humans↗