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[Studies of the relationship between transferrin genetic polymorphism and diseases].

Genetic polymorphism of transferrin (Tf) was investigated in Han nationality population in Guangzhou area using isoelectric focusing technique. In addition, three diseases (Leukaemia, Heptocarcinoma, Systemic-lupus-erythematosis, SLE) were also typed for Tf and compared with that in normal population. The increased TfC1 gene frequency in acute myelocytic leukaemia (AML) patients was found (chi 2 = 4.16, P less than 0.05). The increased frequency of TfC1C1 was also observed (P less than 0.05). Relative Incident(RI) was 1.9 But TfC1 gene and TfC1C1 phenotype frequencies did not increase in ALL, CML and primary heptocarcinoma patients. It suggests that TfC1 may relative to AML in this area. Besides, the increased TfC1 gene frequency was observed in SLE patients (chi 2 x 6.15, P less than 0.025). RI of TfC1C2 was 2.3. It suggests that Tfc2 may relate to SLE in this area.

Adult

Analysis of genetic and environmental sources of variation in serum cholesterol in Tecumseh, Michigan. III. Identification of genetic effects using 12 polymorphic genetic blood marker systems.

Four of 12 unlinked polymorphic marker systems were identified as predictors of normal serum cholesterol levels. Consistent effects between males and females and with other studies suggest that these marker loci are themselves involved in cholesterol determination or are closely linked to the involved loci. Two-locus combinations suggest that an 8-9 mg/100 ml difference in nonfasting serum cholesterol may be predicted between phenotypic classes which are not rare in frequency.

Blood Group Antigens

[Genetic polymorphism of the metabolism of drugs used in cardiac diseases].

The genetic determinants of the metabolism of certain drugs used in cardiology is one predictable cause of variability in their pharmacokinetics and effects. Genetic polymorphism of the metabolism of drugs is characterised by the existence of several metabolic phenotypes, usually 2, which allow distinction between fast and slow metabolisers. Clinical identification of these phenotypes is relatively simple. The enzymatic deficiency in slow metabolisers concerns a specific metabolic pathway responsible for the biotransformation of the drug but it respects other eventual metabolic pathways. For a given drug and a given metabolic pathway, slow metabolisers are unable to eliminate the parent product by hepatic metabolism. When the drug is given orally, the plasma concentrations of the parent product in slow metabolisers are 5 to 25 times higher than those observed in fast metabolisers. Depending on the given drug, doses usually well tolerated by fast metabolisers may cause excessive effects in slow metabolisers. The pharmacodynamic consequences of genetic polymorphism on the metabolism of drugs depend essentially on the therapeutic index of the drug concerned and on the activity of the metabolites formed by the genetically determined pathway of the parent product. The pharmacokinetic and pharmacodynamic consequences of the two main genetic polymorphisms concerning drugs used in cardiology are discussed: the polymorphism of N acetylation and that of cytochrome P-450 IID6.

Acetyltransferases

Genetic polymorphisms in juvenile-onset diabetes.

Nine genetic polymorphic systems (ACP1, PGM1, ADA, AK, G-6-PD, Hp, ABO, Rh, MN), were studied in a series of 138 subjects affected by JOD. Differences between diabetic patients and controls were observed in the distribution of phenotypes of the red cell acid phosphatase (ACP1), and the ABO and MN blood groups.

Acid Phosphatase

Platelet membrane glycoprotein Ib: genetic polymorphism detected in the intact molecule and in proteolytic fragments.

Genetic polymorphism of platelet membrane glycoprotein (GP) Ib was studied in 128 healthy German blood donors using immunoblotting with monospecific anti-glycocalicin antibodies. Only three GP Ib forms (B,C and D) were detected. In a smaller number of Vietnamese individuals analysed for comparison all four polymorphic GP Ib forms were found. The frequency distribution of GP Ib phenotypes in the German population was similar to that reported for U.S. Americans of Caucasian origin. GP Ib polymorphism was also observed in purified glycocalicin samples of single donors. Using trypsin-cleaved glycocalicin the polymorphic region could be located in the C-terminal carbohydrate-rich glycocalicin fragment (macroglycopeptide).

Asian People

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

Genetic polymorphisms in the 5'-flanking region change transcriptional regulation of the human cytochrome P450IIE1 gene.

We identified genetic polymorphisms in the 5'-flanking region of the human cytochrome P450IIE1 gene and investigated the effect of these polymorphisms on the transcriptional regulation of the gene. PCR direct sequencing of the two homozygous alleles [types A (c1/c1) and C (c2/c2)] revealed the existence of several point mutations in the distal 5'-flanking region of the gene, but no differences in the proximal promoter region. The DNA segment (-1372 to -960) placed upstream of SV40 promoter and the chloramphenicol acetyltransferase (CAT) gene enhanced the expression of the gene, and the enhancement of expression by type C DNA was about 10 times that by its type A counterpart. DNase I footprinting analysis showed at least one protected region in which one of the polymorphic loci (RsaI polymorphism) was located. The DNase I sensitivities and protection profiles of the two genotypes were different. The protected region had high homology to the consensus sequence of the binding region of liver specific transcription factor HNF1 (LF-B1), and this was confirmed by gel retardation assay. These results indicate that genetic polymorphisms in the 5'-flanking region of the human P450IIE1 gene affect its binding of trans-acting factor and change its transcriptional regulation. This may lead to inter-individual differences of microsomal drug oxidation activity.

Amino Acid Sequence

Genetic polymorphisms of the A and B subunits of human coagulation factor XIII in mainland Italy and Sardinia: description of a new FXIIIA variant allele.

The distribution of the two alleles of FXIIIA and the three alleles of FXIIIB were studied in populations from mainland Italy and from Sardinia. The frequencies of the FXIIIA*2 allele were 0.266 and 0.265. The frequencies of FXIIIB*1 were 0.787 and 0.765; of B*2, 0.070 and 0.094; of B*3, 0.143 and 0.141. A new cathodal FXIIIA allele (A*7) was described in the Rome sample. No significant difference in the distribution of allele frequencies for either system was found between the two populations studied. For typing both markers, good results were also obtained by using whole blood instead of plasma.

Alleles

Genetic polymorphism of apolipoprotein H (beta 2-glycoprotein I) in African blacks from the Ivory Coast.

The apolipoprotein H (APO H) polymorphism was analyzed in the Negroid population from the Ivory Coast using polyacrylamide gel isoelectric focusing, followed by immunoblotting. The gene frequencies of alleles APO H*1, APO H*2, APO H*3 and APO H*4 were calculated to be 0.012, 0.921, 0.047, and 0.020, respectively. The assumption that APO H*4 represents a Negroid marker allele is supported by this population study.

Alleles

Genetic polymorphism of the gene encoding the outer surface protein A (OspA) of Borrelia burgdorferi.

The genes coding for the outer surface protein (OspA) of Borrelia burgdorferi, the causative agent of Lyme borreliosis have been cloned and sequenced. Two German strains (skin isolate PKo and cerebrospinal fluid isolate PBi) have been analyzed. Using an OspA-specific monoclonal antibody (L32 2E7) for immunological screening of a genomic pUC18 library of B. burgdorferi strain PKo, and OspA-producing clone was detected and subclones containing the open reading frame were constructed. The gene coding for the OspA protein of B. burgdorferi strain PBi was amplified using polymerase chain reaction (PCR) and cloned in pUC8. The open reading frame of both ospA genes consists of 822 nucleotides corresponding to a protein of 273 amino acids. Both proteins have a calculated molecular mass of 29.6 kDa. Molecular analysis revealed significant differences between each other and to already-published sequences of ospA of B. burgdorferi strains B31, ZS7 and N40 (the ospA genes of B31, ZS7 and N40 are nearly identical). The deduced amino acid sequences of the OspA protein of strains PKo and PBi showed a homology of 83% to each other and 77% and 80%, respectively, to OspA protein of strain B31. The three proteins contain a variable middle region, whereas the N and the C terminus are conserved. This unexpected high dissimilarity of the ospA genes may be important in respect to vaccination studies and diagnostic procedures (i.e., development of PCR primers or serodiagnostic antigens). Moreover, the molecular heterogeneity of OspA confirms three out of seven immunologically defined OspA serotypes of a recently proposed OspA serotyping system.

Amino Acid Sequence

Genetic polymorphism of alpha-L-fucosidase in Brittany (France).

The authors studied the phenotypic distribution of alpha-L-fucosidase in a random sample of the population of the area of Rennes (France). The frequencies of Fu1 (0.64) and Fu2 (0.36) genes are significantly different from the frequencies observed in New York whites and blacks.

Adolescent

Genetic polymorphism of human anodal tear protein.

Electrophoresis of human tears on slab polyacrylamide gels showed five phenotypes among anodal tear proteins. These phenotypes are the expression of autosomal codominant alleles. Gene frequencies are as follows: for Caucasians, At1 = 0.99, At3 = 0.01; for Negroes, At1 = 0.97, At2 = 0.03; for Chinese, At1 = 0.98, and At4 and At5 are both approximately 0.008.

Alleles

Genetic polymorphism of human factor H (HF, beta 1H globulin) in Chinese Han population in northeast China.

The distribution of human factor H of serum phenotypes were studied using ultrathin polyacrylamide gel isoelectric focusing (PAGIEF) and subsequent immunoblotting techniques in 203 Chinese of Han population in Liaoning Province of northeast China. The gene frequencies of HF*A and HF*B were 0.4828 and 0.5172, respectively. All the observed numbers of the phenotypes were in agreement with the expected numbers under the Hardy-Weinberg equilibrium. The gene frequencies among Chinese, Japanese, and Caucasian populations were compared.

China

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