Novel duplication in the F12 gene in a patient with recurrent angioedema

Edema formation is mediated by histamine or bradykinin release and may have several hereditary and acquired causes. In hereditary forms of bradykinin-mediated angioedemas, mutations in the genes encoding C1-inhibitor (SERPING1) as well as coagulation factor XII (F12) have been described. We present a novel F12 gene mutation, a duplication of 18 base pairs (c.892_909dup) in a 37-year-old woman with recurrent angioedema and normal C1-inhibitor level. A single episode of facial edema in the family of the patient showed co-segregation with the mutation. This duplication is causing the repeated presence of 6 amino acids (p.298–303) in the same region of factor XII, as those three mutations described previously in cases of hereditary angioedema with normal C1-INH function. These results may confirm the importance of the proline-rich region of factor XII protein in edema formation.     

A quantitative dot immunobinding assay for coagulation factor XII in plasma

A dot immunobinding assay on nitrocellulose (NC) membranes has been developed for the quantification of human coagulation factor XII (F XII). Plasma samples were dotted on to NC filters and F XII was detected using a polyclonal antiserum followed by a radiolabelled antigen overlay. Dilutions of either pooled normal human plasma (NHP) or purified F XII in F XII deficient plasma were used as standards. Quantification was performed by measuring the radioactivity of bound 125I-F XII. Precise measurements of F XII antigen (F XII: Ag) were possible with a sensitivity down to 0.12 ng. Thus, dotting samples containing 0.5 microliter of plasma permitted detection of a F XII concentration corresponding to 1% of the level in NHP. The intra-assay coefficient of variation (CV) was less than 5% and the interassay CV was less than 16%. F XII:Ag in plasma samples of 50 healthy adults ranged from 12 micrograms/ml to 47 micrograms/ml. A good correlation (r = 0.93) existed between F XII:Ag and F XII clot promoting activity (F XII:C) in these samples. NHP contained 24.1 micrograms/ml F XII:Ag confirming earlier results obtained by other methods. In 16 pregnant women levels of F XII:Ag as well as of F XII:C were elevated, but F XII:Ag was disproportionately higher compared with F XII:C. The immunobinding assay has the following advantages: (1) rapid quantification of large numbers of samples is possible, (2) the sensitivity down to 1% of NHP is better than that of several other methods, (3) only very small amounts of both test material and reagents are needed.     

Human genes encoding prothrombin and ceruloplasmin map to 11p11–q12 and 3q21–24, respectively

The gene for human prothrombin, or factor II (F2) has been assigned to 11p11–q12 by the combined use of a panel of somatic cell hybrid DNAs and in situ hybridization, using both cDNA and genomic probes. In addition, the cDNA probe for F2 recognizes a homologous sequence which has been tentatively mapped to the X chromosome. Similar approaches have been used to confirm the assignment of the ceruloplasmin gene, but to regionally localize it more proximally than previously reported (3q21–q24). These results provide further evidence that genes encoding the coagulation factors and related proteins are dispersed throughout the human genome.     

Human muscle cell surface antigen 16.3A5 is encoded by a gene on chromosome 11

A monoclonal antibody (McAb), 16.3A5, has been characterized that reacts with a cell surface antigen of human muscle cells and a variety of nonmuscle cells. The gene controlling synthesis of 16.3AS antigen has been assigned to human chromosome 11 by assessing McAb reactivity on a panel of mouse-human cell hybrids. The 16.3A5 has a novel specificity distinct from other chromosome 11-encoded antigens such as W6/34, F10.44.2, TRA1.10, and 4D12 antigens.     

F12‐46C/T polymorphism as modifier of the clinical phenotype of hereditary angioedema

The factors influencing the heterogeneous clinical manifestation of hereditary angioedema due to C1‐INH deficiency (C1‐INH‐HAE) represent one of the oldest unsolved problems of the disease. Considering that factor XII (FXII) levels may affect bradykinin production, we investigated the contribution of the functional promoter polymorphism F12‐46C/T in disease phenotype. We studied 258 C1‐INH‐HAE patients from 113 European families, and we explored possible associations of F12‐46C/T with clinical features and the SERPING1 mutational status. Given that our cohort consisted of related subjects, we implemented generalized estimating equations (GEEs), an extension of the generalized linear model accounting for the within‐subject correlation. F12‐46C/T carriers exhibited a significantly delayed disease onset (P < 0.001) and did not need long‐term treatment (P = 0.02). In a GEE linear regression model, the presence of F12‐46C/T was significantly associated with a 7‐year delay in disease onset (P < 0.0001) regardless of SERPING1 mutational status. It is concluded that F12‐46C/T carriage acts as an independent modifier of C1‐INH‐HAE severity.     

Isolation,characterization and chromosomal mapping of an actin gene from the primitive red alga Cyanidioschyzon merolae

Based on the results of cytological studies, it has been assumed that Cyanidioschyzon merolae does not contain actin genes. However, Southern hybridization of C. merolae cell-nuclear DNA with a yeast actin-gene probe has suggested the presence of an actin gene in the C. merolae genome. In the present study, an actin gene was isolated from a C. merolae genomic library using a yeast actin-gene probe. The C. merolae actin gene has no intron. The predicted actin is composed of 377 amino acids and has an estimated molecular mass of 42003 Da. Southern hybridization indicated that the C. merolae genome contains only one actin gene. This gene is transcribed at a size of 2.4 kb. When Southern hybridization was performed with C. merolae chromosomes separated by pulsed-field gel electrophoresis, a band appeared on unseparated chromosomes XI and XII. A phylogenetic tree based on known eucaryote actin-gene sequences revealed that C. merolae diverged after the division of Protozoa, but before the division of Fungi, Animalia and Chlorophyta.     

Missense mutation Thr309Lys in the coagulation factor XII gene in a Spanish family with hereditary angioedema type III

Background:  A new type of hereditary angioedema (type III) affecting mainly women with normal C1-inhibitor level and function has been described. Exposition to estrogens is an important precipitating factor. Recently, a missense mutation in the gene of the blood coagulation factor XII (Hageman factor) has been reported in a few families with this type of hereditary angioedema.
Aim:  To study a patient and her family with recurrent swelling attacks during pregnancy.
Methods:  Complement factors C3 and C4 as well as C1-inhibitor level and function were determined. Genomic DNA was isolated from venous blood samples and screened for mutations in the coagulation factor XII gene.
Results:  C3 and C4 levels as well as C1-inhibitor level and function were normal. A missense mutation Thr309Lys was identified in factor XII gene with a heterozygotic pattern. This mutation was also identified in the mother of the patient, her daughter and her son.
Conclusion:  These results support that the mentioned mutation in factor XII gene causes hereditary angioedema type III.     

Regional assignment of human tissue factor gene (F3) to chromosome 1p21-p22

Tissue factor, or coagulation factor III, is a membrane-bound glycoprotein and acts as a cofactor for factor VII-dependent initiation of blood coagulation. The tissue factor gene (F3) was previously assigned to human chromosome 1, region p21-pter. The present report has further refined the mapping position to 1p21-p22 using a cDNA probe for the tissue factor gene and in situ hybridization to metaphase chromosomes.     

Regulation of E2F1 by the von Hippel–Lindau tumour suppressor protein predicts survival in renal cell cancer patients

Biallelic mutations of the von Hippel–Lindau (VHL) gene are the most common cause of sporadic and inherited renal cell carcinoma (RCC). Loss of VHL has been reported to affect cell proliferation by deregulating cell cycle‐associated proteins. We report that the VHL gene product (pVHL) inhibits E2F1 expression at both mRNA and protein level in zebrafish and human RCC cells, while loss of VHL increases E2F1 expression in patient kidney tumour tissue and RCC cells, resulting in a delay of cell cycle progression. RCCs from von Hippel–Lindau patients with known germline VHL mutations express significantly more E2F1 compared to sporadic RCCs with either clear‐cell (cc) or non‐cc histology. Analysis of 138 primary RCCs reveals that E2F1 expression is significantly higher in tumours with a diameter ≤7 cm and with a favourable American Joint Committee on Cancer (AJCC) stage. The expression of E2F1 in RCC significantly correlates with p27 expression, suggesting that increased expression of E2F1 in RCC induces tumour cell senescence via p27. Cox regression analysis shows significant prediction of E2F1 expression for disease‐free survival and overall survival, implying that E2F1 expression in kidney tumour is a novel prognostic factor for patients with RCC. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Lack of evidence for frequent MED12 p.L1224F mutation in prostate tumours from Caucasian patients

Recently mutations in the MED12 gene have been reported in 5.4% of prostate tumours from Caucasian patients analysed by exome sequencing (Barbieri CE, Baca SC, Lawrence MS, et al. Exome sequencing identifies recurrent SPOP, FOXA1 and MED12 mutations in prostate cancer. Nature Genet 2012; 44: 685–689). In more than 70% of prostate tumours with MED12 mutation, a recurrent p.L1224F mutation in exon 26 was found. In order to validate this MED12 p.L1224F mutation, an unselected cohort of prostate tumours from Caucasian patients was analysed by Sanger sequencing. Overall, 223 prostate tumours and three lymph node metastases were analysed. The MED12 p.L1224F mutation could not be detected in any of the cases. So far, the recently reported MED12 p.L1224F mutation could not be validated in our unselected cohort of prostate tumours. Contrary to the findings of Barbieri et al, our data indicate either that the p.L1224F mutation in the MED12 gene plays no role in prostate carcinogenesis or that this alteration is only relevant in a small subgroup of tumours. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

A possible mechanism for maintenance of the deleterious allele of human CASPASE-12

In humans, a functional CASPASE-12 (CASP12) gene has been identified only in persons of African heritage and has been suggested to play a regulatory role in response to bacterial pathogens and in promoting and increased susceptibility to sepsis. The existence of a gene whose effect is deleterious, and which has been the subject of extensive negative selection in the rest of the human population, implies the simultaneous presence of some selective benefit for persons having CASP12. Given the importance of inflammatory immune responses in controlling the initial stages of infection, and the role that CASP12 plays in down-regulating inflammation, we hypothesize that pathogens which exploit the inflammatory response are restrained by an active CASP12 gene product. Several candidate pathogens are discussed.     

Characterization of bovine septicemic, bovine diarrheal, and human enteroinvasive Escherichia coli that hybridize with K88 and F41 accessory gene probes but do not express these adhesins

Certain DNA probes derived from accessory genes of cloned K88 and F41 determinants hybridize with Escherichia coli strains that express K88 or F41 and with certain other E. coli strains that do not express these antigens. We found that these probes hybridized with human enteroinvasive E. coli, and with bovine E. coli isolates which produced a fatal septicemia in experimentally infected piglets. These strains did not hybridize with probes derived from the structural subunit genes encoding the K88 and F41 antigens. E. coli strains isolated from turkeys with septicemia, Shigella and Salmonella strains did not hybridize to the K88 and F41 accessory gene probes. The K88 and F41 accessory gene probes hybridized with a 200 kb plasmid which is required for invasion by human enteroinvasive E. coli. The K88 and F41 accessory gene homology in the bovine isolates was located on a 150 kb transmissible plasmid but was unrelated to plasmids encoding aerobactin, Vir, or colicin V, which are suspected virulence factors in septicemic E. coli. A common plasmid-encoded antigen was associated with bovine isolates that hybridized with the K88 and F41 accessory gene probes. This included strains which express CS31A, a surface antigen associated with bovine septicemic E. coli, which also hybridized with the K88 and F4 accessory gene probes. The results suggest that the K88 and F41 accessory gene probes hybridized with sequences that may be associated with a common mechanism of pilus expression in distinct groups of E. coli pathogens.     

MDR gene transfer into live mice

Conclusions Stable integration of the human MDR gene into the HSC of animals has been used to study the biological properties of the totipotent stem cell. The site of proviral integration of the MDR gene provides a clonal marker that can be used to follow the progeny of transduced HSC throughout differentiation and over time. The expressed protein product, p-glycoprotein, has also been assessed in these studies. MDR gene transfer has potential therapeutic applications in cancer therapy by providing resistance to a number of commonly used chemotherapeutic agents, and as a selection for a cotransduced nonselectable gene. Promising results in the murine system indicate that the transfer and expression of the human MDR gene may prove to be valuable in human gene therapy.Abbreviations BFU-E Burst-forming unit-erythroid - CHO Chinese hamster ovary - CFU-GEMM Colony-forming unit-granulocyte-erythroid-macrophage-monocyte - CFU-GM Colony-forming unit-granulocyte-macrophage - CFU-S Colony-forming units-spleen - FACS Fluorescence activated cell sorting - 5-FU 5-Fluorouracil - HSC Hematopoietic stem cells - PCR Polymerase chain reaction - LIN Lineage-negative - LTR Long terminal repeat - MDR Multiple-drug resistance - PBC Peripheral blood cells - PBPC Peripheral blood progenitor cells - SCF Stem cell factor     

Mutations in the factor IX gene (F9) during the past 150 years have relative rates similar to ancient mutations

Pollutants and dietary mutagens have been associated with somatic mutation and cancer, but the extent of their influence on germline mutation is not clear. Since deleterious germline mutations can be transmitted for thousands of years, any influence on germline mutation from the vast increase in man‐made chemicals of the past 150 years would be an important public health issue. Observed disease causing mutations in the X‐linked factor IX gene (F9) of hemophilia B patients originated predominantly in the past 150 years, since the half‐life of these mutations in human populations had been about two generations before effective treatment became available about a generation ago. Recent changes in germline mutational processes may be detected by comparison of the observed hemophilia B causing mutation pattern in F9 with the pattern of neutral polymorphisms which occurred over a much longer period of time. By scanning a total of 1.5 megabases of deep intronic regions of F9 in the genomic DNA from 84 individuals, 42 neutral polymorphisms were found in 23 haplotypes that differed by at least 11 mutations from the ancestral primate haplotype. By sequencing F9 in seven non‐human primates, 39 of these polymorphisms were characterized as ancient mutations relative to a unanimous ancestral primate allele. This ancient mutation pattern was compared to the recent pattern of hemophilia B causing mutations. Remarkably, no significant difference was found (P=0.5), suggesting that the vast increase in man‐made chemicals during the past 150 years has not had a major impact on the pattern of human germline mutation. This result is consistent with the hypothesis that endogenous processes dominate germline mutation. Hum Mutat 19:49–57, 2002. © 2001 Wiley‐Liss, Inc.     

Fusion of the EWS Gene to a DNA segment from 9q22-31 in a human myxoid chondrosarcoma

Southern blot analyses revealed a rearrangement of the EWS gene in a skeletal human myxoid chondrosarcoma. Interphase fluorescence in situ hybridization (FISH) studies, using cosmid clones F7 and G9 that flank the EWS locus on 22q12, confirmed the presence of this EWS gene abnormality. Cloning the rearranged EWS DNA fragment and mapping by FISH demonstrated that the EWS gene is joined to DNA sequences localised in 9q22-31. These findings are consistent with previous cytogenetic reports of a recurrent t(9;22)(q22-31;q11-12) in the myxoid variant of chondrosarcoma and reveal involvement of the EWS gene in a fourth type of human sarcoma.     

Precise mapping of the EGF receptor gene on the human chromosome 7p12 using an improved fish technique

Summary The gene for epidermal growth factor receptor (EGFR) has been localized to the p14-p12 region of human chromosome 7 by somatic cell hybridization and radioisotopein situ hybridization techniques. In this paper, we report the precise mapping of the EGFR gene to the band p12 of chromosome 7 using a novel method in which fluorescence images fromin situ hybridization and Q-banding are computer graphically merged. The novel procedure is described in detail.     

Genetic mapping of 1,3-β-glucanase-encoding genes in Saccharomyces cerevisiae

Summary The map position of three 1,3--glucanase-encoding genes in S. cerevisiae has been determined following conventional meiotic and mitotic mapping combined with recombinant DNA techniques. EXG1, EXG2 and SSG1 were localized to chromosomes XII, IV and XV, respectively, by hybridizing the cloned genes to Southern blots of chromosomes sepaated by pulsed-field gel electrophoresis, in conjunction with the rad52-1-dependent chromosome-loss mapping technique. Meiotic tetrad analyses further localized the EXG1 gene 6.1 centimorgans centromere-proximal to CDC25 on the right arm of chromosome XII. EXG2 was positioned between LYS4 and GCN2 on the right arm of chromosome IV, at distances of 6.2 centimorgans from LYS4 and 4.9 centimorgans from GCN2. Finally, the SSG1 locus mapped on the right arm of chromosome XV, about 8.2 centimorgans to the centromere-proximal side of HIS3.     

Deletion of the KIT and PDGFRA genes in a patient with piebaldism

We have previously shown that human piebaldism results from mutations of the KIT gene, which encodes the receptor for the mast/stem cell growth factor and is located in chromosome segment 4q12. Using DNA of a patient with piebaldism, mental retardation, and multiple congenital anomalies associated with a 46,XY,del(4) (q12q21.1) karyotype, we carried out quantitative Southern blot hybridization analyses of the KIT gene and the adjacent PDGFRA (platelet-derived growth factor receptor α subunit) genes. The patient was hemizygous for both the KIT and PDGFRA genes, indicating that both of these genes are included within the deleted region. Therefore, deletion of the KIT and PDGFRA genes may account for the piebald phenotype in this patient.© Wiley-Liss, Inc.