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Results for “Genetic polymorphisms”

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At least 649 records · Page 36Linked to original sources
PubMed1981

delta-Aminolevulinate dehydrase: a new genetic polymorphism in man.

A method has been developed for the electrophoretic and quantitative analyses of human red cell delta-aminolevulinate dehydrase (ALADH). The enzyme is under the control of an autosomal gene, with two common codominant alleles. ALADH1 and ALADH2, with frequencies of 0.89 and 0.11, respectively, in the Italian population. Mean phenotypic enzyme activities are nearly identical: 52,. 49 and 55 mIU/g Hb for ALADH 1, 2-1 and 2 phenotypes respectively.

Alleles↗
PubMed1983

Genetic polymorphism of the LW blood group system.

Family studies of rare LW(a-b+) propositi confirm the recent finding based on frequency studies that the LW blood groups are polymorphic in Finland (Sistonen & Tippett, 1982); they are controlled by two alleles LWa (0.97) and LWb (0.03) independent from most other common blood group loci. Lod scores for LW and the loci for 27 markers are presented.

Alleles↗
PubMed1988

Genetic polymorphisms of the Pmo1 and Pmo2 salivary proteins detected by the modified protein staining method.

Two polymorphic proteins, Pmo1 and Pmo2, were found in human parotid saliva by modifying the protein staining method of Sung & Smithies (1969). The inheritance of each polymorphism was controlled by a dominant allele at an autosomal locus. This hypothesis was supported by studies in 50 families including 103 children. The gene frequencies were Pmo1+ = 0.308, Pmo1- = 0.692, Pmo2+ = 0.026, Pmo2- = 0.974. The Pmo1 and Pmo2 proteins reacted immunologically with antisera prepared to salivary proline-rich proteins (Pr and Gl). The isoelectric point was in excess of 8.58. These results showed that the Pmo1 and Pmo2 proteins belong to the basic proline-rich proteins in human parotid saliva.

Child↗
PubMed1989

A new genetic polymorphism in the 16S ribosomal RNA gene of human mitochondrial DNA.

Sequence analysis of the 3' end of the 16S rRNA gene of mitochondrial DNA (mtDNA) revealed a single base change G----A, at position 3010. This mutation was first identified in a patient who had recovered from chloramphenicol-induced aplastic anaemia (CAP-induced AA). A link between this mutation and CAP-induced AA was ruled out by investigating three other similar patients, none of whom had the mutation. This mutation lies within or near the chloramphenicol binding site in a part of the 16S rRNA gene which shows high evolutionary conservation and where polymorphisms have not been previously reported. Hybridization tests with appropriate oligonucleotide probes in 114 individuals reveal that this mutation has a polymorphic frequency of about 14% in Europeans.

Anemia, Aplastic↗
PubMedDate not supplied

CYP17 genetic polymorphism in patients with endometrial hyperplasia and cancer.

We investigated the association of CYP17 gene polymorphism with the risk of having endometrial cancer and a well-known precursor of it, endometrial hyperplasia. Group A (control group) consisted of 35 patients who had histologically proven normal endometrium. Group B and C consisted of 18 and 30 patients who had endometrial hyperplasia with and without atypia, respectively. Group D consisted of 57 patients who had endometrial cancer. Venous blood samples were collected from patients in groups, and polymerase chain reaction was performed to determine the CYP17 gene polymorphism. Significant increase of A1/A1 and a decrease of A1/A2 genotype frequencies have been determined in patients with endometrial cancer and with atypical endometrial hyperplasia. No significant differences were found between groups in the frequency of A2/A2 genotype. There was no significant difference between the groups in the meaning of allele distributions. CYP17 polymorphism had correlation with endometrial atypia and cancer. Related effects of different types of CYP17 gene variants on the progression of hyperplastic endometrial cells into carcinoma should be evaluated in further studies. Progress in this area would help us modulate preventive treatments used in those actual high-risk group patients.

Adult↗
PubMed1994

Genetic polymorphism and activities of human colon alcohol and aldehyde dehydrogenases: no gender and age differences.

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isoenzyme patterns from 69 (men, 47; women, 22) surgical colon mucosal specimens were identified by agarose isoelectric focusing. gamma-ADH was found to be the predominant form in the mucosa, whereas only beta-ADH was detectable in the muscle layer. ALDH1, ALDH2, and ALDH3 were detectable in the mucosa, with cytosolic ALDH1 being the major form. At pH 7.5, the ADH activities in the colon mucosae with the homozygous phenotype (exhibiting gamma 1 gamma 1) and the heterozygous phenotype (exhibiting gamma 1 gamma 1, gamma 1, gamma 2, gamma 2, gamma 2) were determined to be 183 +/- 13 and 156 +/- 30 nmol/min/g tissue, respectively. The ALDH activities in the ALDH2-active and ALDH2-inactive phenotypes were determined to be 40.2 +/- 2.3 and 34.6 +/- 2.0 nmol/min/g tissue, respectively. The lack of significant difference in the ALDH activities between these two phenotypic groups can be attributed to the very low expression of the mitochondrial ALDH2 in the colon mucosa. No significant differences in the ADH or the ALDH activities were found between the men and women studied and between the three age groups (20-40, 49-70, and 72-83 years). The ascending, transverse, descending, and sigmoid colons exhibited similar ADH and ALDH activities. The isoenzyme patterns of ADH and ALDH remained unaltered in colon carcinomas, except that a significant reduction of the enzyme activities was found in the cancer tissue as compared with the adjacent normal portions. it is concluded that human colon mucosa exhibits significant amounts of ethanol- and acetaldehyde-oxidizing activities.

Adult↗
PubMed1997

T-track PCR fingerprinting for the rapid detection of genetic polymorphism.

The diversity of DNA sequences can be analyzed by comparing randomly amplified polymorphic DNA, or restriction fragment length polymorphism fragments of DNA. Such analyses are dependent on the selection of appropriate restriction enzyme(s) and/or primers. We have investigated a simpler approach to providing sensitive and specific genotyping. Cyclic extension of target sequences with dideoxythymidine generates PCR products with variable lengths. We analyzed these variable PCR products by scoring the number of variable bands and comparing the scores (numerical profiles) to establish similarities. We found that the polymorphic lengths of the PCR products were comparable among serologically defined strains. It suggests that this single PCR reaction followed by a one-step electrophoresis yields easily analyzable data that can be compared with data from other gels.

Base Sequence↗
PubMed1990

Genetic polymorphism of sparteine/debrisoquine oxidation: a reappraisal.

Polymorphic oxidation of the sparteine/debrisoquine-type has been shown to account for much of the interindividual variation in the metabolism, pharmacokinetics and pharmacodynamics of an increasing number of drugs, including some antiarrhythmic, antidepressant and beta-adrenoceptor antagonist agents. Impaired hydroxylation of these drugs results from the absence of the enzyme cytochrome P450IID6 in the livers of poor metabolisers, who constitute 6% to 10% of Caucasian populations. The clinical importance of the phenomenon has to be explored further and for most sparteine/debrisoquine-related substrates there is a need for controlled prospective studies to define the consequences to the patient of impaired or enhanced drug oxidation.

Animals↗
PubMed1989

Gene conversion as a possible factor influencing genetic polymorphism.

The ostracode Cytherissa lacustris (Sars) has been obligatorily parthenogenetic at least since the Mesopleistocene. Old and large populations of it from the lakes of the Salzkammergut area in Austria exhibit quite high polymorphism and quasi-Mendelian proportions at the locus coding for glucose-6-phosphate isomerase. It is argued that this polymorphism has been attained through generations owing to gene conversion operating on the basis of the founder effect, mutations and migration; the effects of gene conversion were then amplified by selection and/or by random events.

Electrophoresis, Starch Gel↗
PubMed2005

Influence of CYP2C9, 2C19 and 2D6 genetic polymorphisms on the steady-state plasma concentrations of the enantiomers of fluoxetine and norfluoxetine.

The antidepressant fluoxetine is administered as racemic mixture of two enantiomers (S- and R-fluoxetine). While S- and R-fluoxetine are equipotent in blocking serotonin reuptake, the enantiomers of the demethylated metabolite, norfluoxetine, show marked differences in pharmacological activity, S-norfluoxetine being about 20 times as potent as R- norfluoxetine as a serotonin reuptake inhibitor. In vitro and in vivo data suggest that the metabolism of fluoxetine to norfluoxetine is stereoselective and mediated, at least in part, by the polymorphic cytochrome P450 (CYP) isoenzymes CYP2D6, CYP2C9 and CYP2C19. In the present study, the influence of CYP2D6, CYP2C9 and CYP2C19 polymorphisms on the steady-state plasma concentrations of fluoxetine and norfluoxetine enantiomers was evaluated in 78 patients receiving chronic fluoxetine treatment (10-60 mg/day). The plasma concentrations of fluoxetine and norfluoxetine enantiomers were measured and CYP2D6, CYP2C9 and CYP2C19 genotypes were analyzed. No statistically significant relationship was identified between CYP2D6 or CYP2C19 genotypes and the dose normalised plasma concentrations of any of the enantiomers or the active moiety (i.e. the sum of S-fluoxetine, R-fluoxetine and S-norfluoxetine). However, the plasma concentration of S-norfluoxetine was very low in the only CYP2D6 poor metaboliser. Furthermore, the median S-norfluoxetine/S-fluoxetine ratios were higher in homozygous than in heterozygous extensive metabolisers (P<0.05). Among homozygous extensive metabolizers for CYP2D6, patients homozygous for CYP2C9*1 had lower dose-normalized R-fluoxetine concentrations and lower active moiety levels compared with those carrying detrimental CYP2C9 alleles (P<0.05). These results suggest that CYP2D6 and CYP2C9 polymorphisms contribute to the interindividual variability in fluoxetine pharmacokinetics at steady-state.

Adolescent↗
PubMed1976

PGM3 locus and its genetic polymorphism in leucocytes of goats.

PGM3 activity was investigated in 150 'Boerbok' goats and 132 Angora goats by means of horizontal starch gel electrophoresis. In 'Boerbok' goats no polymorphism was found. In Angora goats three different phenotypes have been recognized: F, S, and FS. The results suggest the occurrence of two common alleles: PGM3-F and PGM3-S at an autosomal locus with frequencies of 0.6176 and 0.3824, respectively.

Alleles↗