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At least 973 records · Page 54Linked to original sources
PubMed1995

Genetic polymorphism of alpha-2-HS-glycoprotein in northern Bavaria (Germany). Simplified AHSG-phenotyping by isoelectric focusing using dry gels.

A simple and practical method of detecting AHSG using isoelectric focusing on dry gels is described. The procedure is both rapid and provides reliable results. AHSG phenotypes were determinated in 215 unrelated individuals from Northern Bavaria. The allele frequencies obtained were: AHSG*1 = 0.7139, AHSG*2 = 0.2697 and AHSG*3 = 0.0164.

Blood Proteins↗
PubMed1996

Genetic polymorphism of the 3' VNTR region of the human dopaminergic function gene DAT1 (human dopamine transporter gene) in the Mongolian population.

The hypervariable region of the dopamine transporter gene (DAT1) was amplified from samples in the Mongolian population. This region includes a variable number of tandem repeats of a 40-bp core unit in the 3' untranslated region of DAT1. Vandenbergh et al. (1992) reported variability in the number of repeats of this 3' flanking region ranging from 3 to 11 times in white and black populations. We examined polymorphism at the DAT1 locus in 78 native Mongolian subjects. We found alleles with 7 to 13 repeats, which is different from the findings of Vandenbergh et al. (1992). The allele distribution of the Mongolian population is similar to that in the Japanese population, reported previously by Nakatome et al. (1995). Chi-square analysis showed a significant lack of homogeneity between our findings in Mongolian subjects and those reported previously in white and black populations. The DAT1 locus was estimated to have a heterozygosity index of 14.1%, and the polymorphic information content was calculated to be 0.16.

Base Sequence↗
PubMed1996

Clinical application of genetic polymorphism in neurofibromatosis type 1.

The authors report the study of DNA polymorphic sequences, 5 intragenic and 5 flanking the NF1 gene, in 87 Italian NF1 families for a total of 142 affected individuals and 204 non-affected relatives. All PCR-based analyses are easy and simple to perform, and require small amounts of DNA. The non radioactive method used is sensitive, rapid, and has low background. All subjects were informative for at least 2 markers. The use of linkage study to familial cases allowed us to exclude the diagnosis prenatally in two fetuses, and to confirm or exclude diagnosis in those relatives with clinical signs, but not fulfilling the international diagnostic criteria. Furthermore indirect analysis permitted the detection of large gene deletions by loss of heterozygosity of one or more DNA markers in three out of 47 sporadic cases.

Female↗
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↗
PubMedDate not supplied

Clinical importance of genetic polymorphism of drug oxidation.

Certain individuals have a metabolic deficiency in the metabolism of debrisoquin, sparteine, dextromethorphan, and more than 80 other clinically important drugs. Examples of such drugs include tricyclic antidepressants, neuroleptics, selective serotonin reuptake inhibitors, beta-adrenoceptor blockers, and antiarrhythmics. CYP2D6, the enzyme responsible for the metabolism of these drugs, is polymorphically distributed in different populations. Studies in different ethnic groups in particular demonstrate significant variation. CYP2D6 deficiency has important therapeutic consequences, such as increased side effects when medications that are substrates of this enzyme are prescribed for such individuals. To optimize drug therapy, physicians should therefore determine the metabolic capacity of their patients.

Biotransformation↗
PubMed1997

Apolipoprotein B and E genetic polymorphisms in the Cayapa Indians of Ecuador.

Three DNA polymorphisms (XbaI, EcoRI, and Ins/Del) of the apolipoprotein B (APOB) gene and the CfoI polymorphism of the APOE gene were investigated in a sample of 96 Cayapa Indians from Ecuador. The frequencies of the X+ (0.182), R+ (1.000), and Del alleles (0.432) at the three APOB sites were found to be higher than and to differ significantly from those reported for East Asians. No comparisons could be made between the Cayapa and other native Americans because of the lack of data on these sites. We observed in our sample that, like native American populations but unlike East Asians, the APOE allele frequencies were characterized by the absence of the APOE*2 allele and by a high frequency of the APOE*4 allele (0.280). Besides a probable drift effect, the high APOE*4 value was tentatively attributed to an effect of selection. Because this allele enhances the absorption of cholesterol by the intestine, it could confer an advantage to carriers in an unfavorable environment (i.e., diet poor in cholesterol).

Adult↗
PubMed1997

[Genetic polymorphism in sparteine oxidation--occurrence in healthy volunteers in Slovakia].

The aim of this study was to estimate the occurrence of the phenotype of poor metabolizers of sparteine (in the frame of sparteine-debrisoquine-dextromethorphane polymorphism) in Slovakia. The authors examined a group of 216 of healthy volunteers (73 women and 143 men, average age of the group 24, 9 +/- 0.4 years), university students coming from various regions of Slovakia. The test substance-sparteine (1 x 100 mg tbl.) was administered perorally to all probands, in the evening after fasting. A 12-hour gathering of urine was subsequently performed. A sample of urine was subdued to examination. Isolation, separation, identification and assessment of the concentration of sparteine and its metabolites (2- and 5-dehydrosparteine) were performed by the method of gas chromatography. The metabolic MR ratio calculated from the ratio of the detected concentrations of sparteine and (2- and 5-dehydrosparteine) served for the assessment of the phenotype of poor (MR > 20), or rapid (MR < 20) metabolizers of sparteine in 8 authors found the poor metabolizer phenotype of 216 examined probands (i.e. in 3.75%). Its prevalence of the presented phenotype was lower than that anticipated on the basis of epidemiologic studies performed in other European countries. Study represents the first data on the phenotype of poor sparteine metabolizers in Slovakia. (Tab. 4, Fig. 1, Ref. 24.)

Adult↗
PubMed1997

Myeloperoxidase genetic polymorphism and lung cancer risk.

Myeloperoxidase is a lysosomal enzyme found in high concentrations in human lung due to recruitment of neutrophils. Myeloperoxidase activates benzo[a]pyrene as well as aromatic amines in tobacco smoke and generates carcinogen-free radicals. A single base substitution (G to A) in the promoter region of the myeloperoxidase gene has recently been demonstrated to markedly reduce transcription. We developed an RFLP/PCR assay to test the hypothesis that the allele favoring lower transcription (A allele) reduces the risk of lung cancer. Among population controls, 7.8% of 459 Caucasians and 9.4% of 244 African-Americans inherited two copies of the A allele. Caucasians with the A/A genotype were at 70% reduced risk of lung cancer (odds ratio, 0.30; 95% confidence interval, 0.10-0.93; P = 0.04; 182 cases). A lesser reduction in risk was observed for African-Americans with this genotype (odds ratio, 0.61; 95% confidence interval, 0.26-1.41; 157 cases). Individuals who inherit two copies of an allele that reduces transcription of the myeloperoxidase gene may be at decreased risk of lung cancer.

Adult↗
PubMed1997

[Effects of genetic polymorphism of phosphoglucomutase identifiable in human milk (PGM4 locus) on the somatotype of the newborn and reproductive function of women].

The polyacrylamide gel isoelectrofocusing technique was used to examine structural variations of the human milk-expressed enzyme PGM4-locus phosphoglucomutase. Six phenotypes controlled by four alleles: PGM4*1, PGM4*2, PGM4*3, PGM4*4 with frequencies of 0.261, 0.664, 0.047, 0.028, respectively, were identified in 180 milk samples taken from Moscow Russian women in labour. The empirical distribution of the PGM4 phenotypes is in a moderate agreement with the expected one with chi 2 = 9.622; 6 d.f. (p > 0.05). Its phenotypic belonging to PGM4 1-2 and PGM4 2-2 was examined for its influence on female reproductive function and neonatal somatic type. The PGM4 1-2 phenotype was positively associated with miscarriages whereas PGM4 2-2 negatively correlated with this abnormality. If the mother had PGM4 2-2, there might be increased body dimensions (body length and mass, head and chest circumferences) in male neonates. On the contrary, PGM4 1-2 was negatively correlated with body length and mass in the newborns of both sexes. For female neonates, there was a highly significant association only with the presence of PGM4 2-2 in their mothers, namely: its presence was positively correlated with all body dimensions.

Chromosome Mapping↗
PubMed1998

A common genetic polymorphism (46 C to T substitution) in the 5'-untranslated region of the coagulation factor XII gene is associated with low translation efficiency and decrease in plasma factor XII level.

We studied the Hga I polymorphism (46 C/T) in the 5'-untranslated region of the coagulation factor XII (FXII) gene corresponding to four bases upstream from the ATG translation initiation codon. By using allele-specific restriction analysis with restriction endonuclease Hga I, the allele frequency of 46C/T was estimated to be 0.27/0.73 in Orientals (allele number =152), and conversely, 0.8/0.2 in Caucasians (allele number =40). Because it has been reported that plasma levels of FXII were lower in Orientals than in Caucasians, we investigated the relationship between this polymorphism and plasma levels of FXII. As a result, there were significant differences in plasma FXII levels between these three allele types: C/C,170+/-38% (178+/-27%); C/T, 141+/-29% (123+/-34%); and T/T, 82+/-19% (61+/-11%) [FXII activity (FXII antigen levels)]. In heterozygotes of 46 C/T both alleles were equally transcribed in hepatocytes, as determined by reverse transcription polymerase chain reaction (RT-PCR), suggesting little influence of the polymorphism at the level of transcription or on the stability of mRNA. In in vitro transcription/translation analysis, less FXII was produced from cDNA containing 46 T than from that containing 46 C. Therefore, it is highly likely that the 46 T polymorphism in the FXII gene decreased the translation efficiency and led to low plasma levels of FXII activity and antigen, probably due to the creation of another ATG codon and/or impairment of the consensus sequence for the translation initiation scanning model.

Adolescent↗
PubMed1998

Genetic polymorphisms in catechol-O-methyltransferase, menopausal status, and breast cancer risk.

Polymorphic catechol-O-methyltransferase (COMT) catalyzes the O-methylation of estrogen catechols. In a case-control study, we evaluated the association of the low-activity allele (COMT(Met)) with breast cancer risk. Compared to women with COMT(Val/Val), COMT(Met/Met) was associated with an increased risk among premenopausal women [odds ratio (OR), 2.1; confidence interval (CI), 1.4-4.3] but was inversely associated with postmenopausal risk (OR, 0.4; CI, 0.2-0.7). The association of risk with at least one low-activity COMT(Met) allele was strongest among the heaviest premenopausal women (OR, 5.7; CI, 1.1-30.1) and among the leanest postmenopausal women (OR, 0.3; CI, 0.1-0.7), suggesting that COMT, mediated by body mass index, may be playing differential roles in human breast carcinogenesis, dependent upon menopausal status.

Body Mass Index↗