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Results for “Genetic polymorphisms”

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At least 955 records · Page 53Linked to original sources
PubMed1995

Cytochrome P4501A1 and glutathione S-transferase (M1) genetic polymorphisms and postmenopausal breast cancer risk.

Polycyclic aromatic hydrocarbons, possible human breast carcinogens, are metabolized by cytochrome P4501A1 (CYP1A1) and glutathione S-transferase (GSTM1). A CYP1A1 polymorphism (isoleucine to valine substitution in exon 7) or the null allele for GSTM1 may affect the mutagenic potential of polycyclic aromatic hydrocarbons. We examined polymorphisms in GSTM1 and CYP1A1 in relation to breast cancer risk. Included were 216 postmenopausal Caucasian women with incident breast cancer and 282 community controls. DNA analyses suggested no increased breast cancer risk with the null GSTM1 genotype [odds ratio (OR) = 1.10; CI, 0.73-1.64], although there was some indication that the null genotype was associated with risk among the youngest postmenopausal women (OR = 2.44; CI, 0.89-6.64). Slightly elevated risk was associated with the CYP1A1 polymorphism (OR = 1.61; CI, 0.94-2.75) and was highest for those who smoked up to 29 pack-years (OR = 5.22; CI, 1.16-23.56). Statistical power to detect an effect may be limited by small numbers, and larger sample sizes would be required to corroborate these suggestive findings.

Age Factors↗
PubMedDate not supplied

[The genetic polymorphism of cereals demonstrated by PCR with random primers].

Polymerase chain reaction of DNA amplification with the use of random primers is a new approach in investigations of genome specificity. Nucleotide sequences that showed polymorphism in RFLP analysis were used as primers. Optimal temperature conditions and Mg2+ concentrations were determined for studying inter- and intraspecific DNA polymorphism in the most important cereals.

Base Sequence↗
PubMed1995

Protein loss and genetic polymorphism of apolipoprotein(a) modulate serum lipoprotein(a) in CAPD patients.

Lipoprotein(a) (Lp(a)) serum concentrations and apoprotein(a) isoforms were measured in 64 uraemic patients treated with continuous ambulatory peritoneal dialysis (CAPD) and compared with those in 155 normal controls. The mean Lp(a) values were 44 +/- 5 mg/dl (median 30 mg/dl) in CAPD patients and 22 +/- 3 mg/dl (9 mg/dl) in controls (P < 0.01). Within the most common apo(a) isoform classes, higher concentrations of Lp(a) were seen in the CAPD patients compared with the controls (P < 0.05). These results were not influenced by differences in the frequency distribution of the apo(a) isoforms. Twenty-six CAPD patients (41%) were suffering from coronary artery disease and 63% of these patients exhibited low-molecular-weight isoforms < or = S2, compared with 31% of the patients without coronary artery disease. Furthermore a positive correlation between the daily protein (r = 0.4, P = 0.02) and albumin loss (r = 0.39, P = 0.2) into the dialysis fluid and the Lp(a) serum concentration was also observed. Therefore we suggest that the elevated Lp(a) concentrations in CAPD patients are influenced by the amount of protein loss into the dialysate and by the allelic variation of the apo(a) isoform. In addition to the typical dyslipidaemia found in CAPD patients, high levels of Lp(a) and specific isoform patterns may in turn contribute to the elevated risk of coronary artery disease and other cardiovascular complications.

Adolescent↗
PubMedDate not supplied

Inter-individual differences of 4-[4-(4-methylphenyl)-phenylmethoxy-1-piperidinyl]butyric acid disposition in rats: possible involvement of genetic polymorphism.

Inter-individual differences of drug plasma concentration were recognized in outbred rats after an oral or intravenous administration of (+)-4-[4-(4-methylphenyl)phenylmethoxy-1-piperidinyl]butyric acid hydrochloride ((+)-MPPB). Rats could be divided into two phenotypes, the rapid metabolizing (RM) group and the slow metabolizing (SM) group. The hepatic clearance of RM-phenotyped Sprague-Dawley rats was about 10 times larger than that of the SM group. Outbred male and female Sprague-Dawley rats and male Wistar rats were mixtures of the RM and SM groups. On the other hand, all inbred male Lewis rats were RM, and all inbred male F344 and ACI rats were SM. This study was undertaken to investigate the inter-individual differences of (-)-MPPB and the metabolic pathways of (+)- and (-)-MPPB. When (-)-MPPB was orally administered to male Sprague-Dawley rats, similar inter-individual differences of plasma concentration were recognized. RM-phenotyped Sprague-Dawley rat liver microsomes metabolized (+)-MPPB to 4-hydroxymethylphenyl-MPPB (M1), and (-)-MPPB to M1 and 4'-hydroxyphenyl-MPPB (M2). The formation of these metabolites was less with SM-phenotyped than with RM-phenotyped Sprague-Dawley rat liver microsomes. The kinetic parameters of M1 formation from (+)-MPPB by RM-phenotyped rat liver microsomes were characteristic of a two-enzyme system with a 100-fold difference in their affinities (KM values). On the other hand, SM-phenotyped rats have only the low-affinity enzyme system. An inhibition study demonstrated that both enzymes were cytochrome P450.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1993

Genetic polymorphisms in a rural Osetian community.

Data are presented on ABO, Rhesus, MNSs, P, Duffy, Kell and Kidd blood group polymorphisms in the Dzhava district, located on the southern slopes of the Main Caucasian Mountain Range. The gene frequencies, compared with those in other Osetian populations and neighbouring ethnic groups of the Caucasus, show general similarity. An exception to the general pattern is presented only by the P blood group system, where the frequencies of the alleles are significantly different form those observed in the neighbouring populations.

Blood Group Antigens↗
PubMed1995

[Frequency of genetic polymorphism (Arg353-->Gln) and factor VII levels in Japanese healthy adults].

We studied factor VII levels and frequency for a G-to-A substitution resulting in the replacement of glutamine for arginine at codon 353 of factor VII by Msp I polymorphism in 101 Japanese healthy adults. An homozygote and seven heterozygotes for the factor VII Gln 353 allele was found in the samples. The frequency of Japanese was not different from those of populations of the United Kingdom, Europe and Afro-Caribbeans, but was different from that in Gurjarati Indians (0.25) previously reported by Humphries et al (Arch Pathol Lab Med 116:1322-1329, 1992). The homozygote had the lowest levels (factor VII activity; 50% and factor VII antigen; 45%) in all samples. The seven heterozygotes had levels of factor VII activity and factor VII antigen about 25% lower than those with only the arginine allele. There were no difference in the levels of factor VII between smoking and no smoking heterozygotes, and between those taking fatty and non-fatty diet.

Adult↗
PubMed1993

Genetic polymorphism of HLA-DR in the Japanese population.

As a result of carrying out sequence analyses on the HLA-DR genes of several Japanese donors, we found three new DRB1 alleles, DRB1-12b, DRB1-14c, and DRB1-JX6, that had not been identified using immunological procedures. Sequence-specific oligonucleotide (SSO) probes directed against various DRB1 alleles, including the above three, enabled DNA typing of all the DRB types in the Japanese population and calculation of their gene frequencies based on this typing to be carried out for the first time. The SSO-DNA typing yielded higher DR13 and DR14 gene frequencies than those reported by serological workshops. Next, we applied this DR-DNA typing to the analysis of Japanese patients with juvenile rheumatoid arthritis (JRA) and found that DRB1*0405 was the allele susceptible to rheumatoid factor-positive polyarticular JRA, which is one of the four types of JRA that has been classified clinically. Analysis of the DR types of patients who suffered unexplained recurrent spontaneous abortion (URSA) using DNA typing demonstrated that 1) URSA is not correlated with any particular DR type and 2) no difference between the DR sharing rate of patients and normal couple was detected, which contradicts the results obtained in some serological studies.

Alleles↗
PubMed1993

Genetic polymorphism of factor B (Bf) and C3 component of complement in type 1 (insulin-dependent) diabetes mellitus: BFQO allele observed in a diabetic child.

C3 and Bf polymorphisms were studied in 215 and 192 children with type 1 diabetes mellitus (IDDM), respectively. No significant differences in C3 phenotypes and allele frequencies were found between IDDM patients and a healthy population. The rare allele BfF1 was found in 9.37% of diabetic patients but in only 0.35% of the general Slovak population (0.0468 vs. 0.0017). An increased frequency rate of BfSO.7 was also observed in 8.85% of IDDM patients compared with 3.57% of healthy controls (0.0442 vs. 0.0178). The relative risk was 28.83 for BfF1 and 2.55 for BfSO.7. One diabetic child was found to be heterozygous for a silent allele BfQO. This rare Bf allele was transmitted to the boy from his healthy mother.

Adolescent↗
PubMed1993

Genetic polymorphism of prophenoloxidase A1 in Drosophila melanogaster.

Electrophoretic variations of prophenoloxidase were obtained from natural populations of Drosophila melanogaster. A1, one of the 2 isoforms of the prophenoloxidases, is polymorphic: 10 fast-migrating and 2 slow-migrating types were found in polyacrylamide gel electrophoresis among 271 wild strains. The majority were the intermediate-migrating type. By use of these variants, A1 gene was mapped at 79.6 on the right arm of the second chromosome. By deletion mapping, its cytological position was located at 55A-B. In the electropherograms, hybrids between the types differing in mobility exhibited 3 bands, indicating that A1 is a dimeric protein. The gene for A1 is expressed through larval, pupal and adult stages.

Animals↗
PubMed1993

Genetic polymorphisms of the A and B subunits of coagulation factor XIII in the Chinese population.

Coagulation factor XIIIA and XIIIB polymorphisms in a random population sample from Chengdu in southwest China (n = 121) were studied using isoelectric focusing in polyacrylamide gels followed by immunoblotting with enzyme immunoassay. The allele frequencies were as follows: FXIIIA*1 = 0.8719, FXIIIA*2 = 0.1240, FXIIIA*3 = 0.0041; FXIIIB*1 = 0.2727, FXIIIB*2 = 0.0165, FXIIIB*3 = 0.7107. The distribution of phenotypes of FXIII agrees with the Hardy-Weinberg equilibrium. Comparing these allele frequencies with those reported in other populations, it was found that the allele frequencies of FXIIIA*1 and FXIIIB*3 in the Chinese population were higher.

Alleles↗
PubMed1993

[Genetic polymorphism of haptoglobin and quantitative changes in its levels during exposure to asbestos].

The polymorphism and serum levels of haptoglobin were studied in asbestosis patients, in the control and the workers exposed to asbest. Hp1-1 has the highest, Hp2-2--the lowest and Hp2-1 has the intermediate concentration of this protein. In the course of contact with asbest, and especially in asbestosis patients, the haptoglobin levels are higher (for all phenotypes). The standard deviation from the Hp concentration in asbestosis patients was significantly higher. The phenotypes Hp1-1 were found more often in asbestosis patients than among asbest-exposed workers.

Asbestos↗
PubMed1993

Hemopexin: a unique genetic polymorphism in populations of African ancestry.

Using isoelectric focusing and immunoblotting techniques, we have screened 937 plasma or serum samples from Nigerian blacks (N = 380), Papua New Guineans (N = 110), Aleuts (N = 62), Mayans (N = 139), Dogrib Indians (N = 45), and Eskimos from Kodiak and St. Lawrence islands (N = 201) for the hemopexin (HPX) polymorphism. We compared these data with our previously published data for US whites (N = 267) and US blacks (N = 194). Except for Nigerian blacks and US blacks, HPX was found to be monomorphic for the common HPX*1 allele in all populations tested. In addition to the commonly occurring HPX*1 allele, two other less common alleles, HPX*2 and HPX*3, were observed with respective frequencies of 1.8% and 4.6% in US blacks and 1.7% and 9.0% in Nigerian blacks. These data strongly suggest that the HPX*2 and HPX*3 alleles are unique alleles restricted to the black gene pool and are of potential significance in microevolutionary studies and in defining African admixture in hybrid populations. In addition to their importance in anthropogenetic studies, these unique HPX mutations also have potential biological significance in hemolytic disorders.

Africa↗