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Engström PE, Gustafson R, Granberg M, Engström GN. Specific IgA subclass responses in serum and saliva: a 12-month follow-up study after parenteral booster immunization with tetanus toxoid. Acta Odontol Scand 2002; 60:198-202. [PMID: 12222642 DOI: 10.1080/000163502760147945] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Specific IgA subclass antibodies against tetanus toxoid in serum, parotid saliva, and whole saliva were quantified after booster immunization. Samples from 14 healthy individuals were collected before and 1, 6, and 12 months after subcutaneous injection with Duplex (0.23 ml tetanus toxoid 30 Lf/mL and diphtheria 7.3 Lf/mL). Samples of whole saliva were also collected after 2 weeks. Specific IgA1 and IgA2 subclass antibodies to tetanus toxoid were quantified by enzyme-linked immunosorbent assay (ELISA). In this quantitative method, chimeric IgA1 and IgA2 antibodies directed against NP (4-hydroxy-3-nitrophenacetyl) were used as standards. Total levels of IgA1 and IgA2 were measured using a nephalometer or ELISA. Immunization with tetanus toxoid resulted in raised mean values of specific IgA1 and IgA2 antibodies against tetanus toxoid in serum after 1 month. Compared with the baseline, the mean value of specific IgA1 antibodies showed a 2.6-fold increase (mean value 10.47 microgram/mL) in serum, and that of specific IgA2 antibodies a 2.7-fold increase (mean value 0.93 microgram/mL). Specific IgA subclass antibody levels in parotid and whole saliva were unchanged after 1 month. The ratio of specific IgA subclass antibodies to total IgA subclass antibodies was 3 to 10 times higher in parotid saliva compared with whole saliva. In conclusion, subcutaneous booster immunization with tetanus toxoid induced immune responses of both antigen-specific IgA1 and IgA2 subclass antibodies in serum with the same increase, whereas the levels of specific IgA subclass antibodies in secretory fluids were unchanged. The ratio of specific IgA subclass antibodies to immunoglobulins was higher in parotid saliva compared with whole saliva.
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Affiliation(s)
- Per-Erik Engström
- Department of Microbiology, Pathology and Immunology, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden.
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2
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Terada T, Kaneko H, Li AL, Kasahara K, Ibe M, Yokota S, Kondo N. Analysis of Ig subclass deficiency: First reported case of IgG2, IgG4, and IgA deficiency caused by deletion of C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon in a Mongoloid patient. J Allergy Clin Immunol 2001; 108:602-6. [PMID: 11590388 DOI: 10.1067/mai.2001.118293] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The cause of Ig class or subclass deficiencies has been unclear except for IgH gene deletions and a homozygous 1-base insertion (1793insG) in C gamma 2 exon 4 of IgG2 deficiency. In addition, there are no reports that IgH gene deletions are found in patients who are Mongoloid (a category that includes most of the people of Asia, such as the Japanese, Chinese, Indonesians and Malaysians). OBJECTIVE To investigate the cause of Ig subclass deficiency, we extensively investigated 4 Japanese patients with low serum IgG2 levels. Patient 1 was a 23-month-old girl whose serum IgG2, IgG4, and IgA levels were under the detection limits; she also had idiopathic thrombocytopenic purpura. Patient 2 was a 5-year-old boy whose serum IgG2 level was under the detection limit. Patient 3 was a 14-month-old boy whose serum IgG2 and IgG4 levels were under the detection limits. Patient 4 was 3-year-old girl whose IgG2 level was low and whose IgA level was under the detection limit. METHODS DNA was extracted from neutrophils, and Southern blot analysis was performed. RESULTS Southern blot analysis revealed that patient 1 had lost the C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon genes and was a homozygous carrier of the deletion described above. Her mother was of the heterozygous genotype. DNA from patients 2, 3, and 4 revealed no deletions in comparison with control DNA. CONCLUSION This is a report of the first case of a Mongoloid in whom IgG2, IgG4, and IgA deficiency was caused by deletion of C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon. Our finding contributes to investigations of Ig subclass deficiency.
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Affiliation(s)
- T Terada
- Department of Pediatrics, Gifu University School of Medicine, Japan
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3
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Brusco A, Saviozzi S, Cinque F, Bottaro A, DeMarchi M. A Recurrent Breakpoint in the Most Common Deletion of the Ig Heavy Chain Locus (del A1-GP-G2-G4-E ). THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.8.4392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Human Ig heavy chain constant regions are encoded by a cluster of genes, the IGHC locus, on 14q32.3. Several forms of IGHC deletions and duplications spanning one to five genes have been described in different populations, with frequencies of 1.5–3.5% and 4.5–44%, respectively. Despite the common occurrence of these gene rearrangements, little is known about the breakpoint sites; evidence obtained from deletions in the IGHC locus and in other regions of the human genome suggests that they preferentially occur in highly homologous regions and might be favored by a variety of recombinogenic signals. We present here a detailed study of three homozygotes for the most common type of IGHC multiple gene deletion, spanning the A1-GP-G2-G4-E genes. Using a combination of Southern blotting, long-range PCR, and automated sequencing, the unequal crossover events of all of the six studied haplotypes have been mapped to a region of ∼2 kb with almost complete homology between EP1-A1 and E-A2, flanked by two minisatellites. These results are consistent with the hypothesis that segments of complete homology may be required for efficient homologous recombination in humans. The possible role of minisatellites as recombination signals is inferred, in agreement with current knowledge.
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Affiliation(s)
- Alfredo Brusco
- *Dipartimento di Genetica, Biologia e Biochimica, Università di Torino, Torino, Italy
| | - Silvia Saviozzi
- *Dipartimento di Genetica, Biologia e Biochimica, Università di Torino, Torino, Italy
| | - Fernanda Cinque
- *Dipartimento di Genetica, Biologia e Biochimica, Università di Torino, Torino, Italy
| | - Andrea Bottaro
- †Departments of Medicine and Microbiology and Immunology, and Cancer Center, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642; and
| | - Mario DeMarchi
- ‡Dipartimento di Scienze Cliniche e Biologiche, Università di Torino, Torino, Italy
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4
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Engström PE, Norhagen G, Osipova L, Helal A, Wiebe V, Brusco A, Carbonara AO, Lefranc G, Lefranc MP. Salivary IgG subclasses in individuals with and without homozygous IGHG gene deletions. Immunology 1996; 89:178-82. [PMID: 8943711 PMCID: PMC1456487 DOI: 10.1046/j.1365-2567.1996.d01-738.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In this study, the levels of salivary IgG1, IgG2, IgG3 and IgG4 from individuals with and without homozygous immunoglobulin heavy chain constant gene deletions were quantified by enzyme-linked immunosorbent assay (ELISA). To analyse the restriction of salivary IgG subclasses, we used unstimulated whole saliva and sera collected at the same time from individuals with homozygous gene deletions, two with G1 deletion, one with G4 deletion, six with both G2 and G4 deletions and from eight individuals without IGHG gene deletions and expressing all four IgG subclasses. The median values of salivary IgG from individuals with homozygous G1, or G4, or both G2 and G4 deletions, and from individuals expressing all four subclasses were 24.2 mg/l and 23.4 mg/l, respectively. The median values of serum IgG were 13.7 g/l and 15.9 g/l, respectively. Our results show that the salivary and serum IgG levels were both within the normal range in individuals with homozygous gene deletions of either G1, or G4, or both G2 and G4.
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Affiliation(s)
- P E Engström
- Department of Immunology, Microbiology, Pathology and Infectious Diseases, Karolinska Institute, Huddinge, Sweden
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5
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Rabbani H, Kondo N, Smith CI, Hammarström L. The influence of gene deletions and duplications within the IGHC locus on serum immunoglobulin subclass levels. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1995; 76:S214-8. [PMID: 7554471 DOI: 10.1016/s0090-1229(95)90270-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To study the influence of heterozygous gene deletions and duplications in the human IGHC region on serum concentrations of antibodies, we have analyzed the IgG subclass levels in a large number of individuals from three different populations. Our results show that heterozygous gene deletions of the C gamma 1, C gamma 2, or C gamma 4 genes are all associated with a lower mean serum level of the affected subclass whereas duplication of the C gamma 2 or C gamma 4 genes result in either no change (IgG2) or a slightly elevated (IgG4) level of serum immunoglobulins.
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Affiliation(s)
- H Rabbani
- Center for BioTechnology, Karolinska Institute, NOVUM, Huddinge, Sweden
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6
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Depelchin S, Dehennin JP, Bottaro A, Carbonara A, Vaerman JP, Sibille Y. Validation of IgA1 and IgA2 measurements by a solid-phase immunoradiometric assay in serum and secretions. INTERNATIONAL JOURNAL OF CLINICAL & LABORATORY RESEARCH 1994; 24:154-61. [PMID: 7819595 DOI: 10.1007/bf02592446] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We describe specific, sensitive and reproducible immunoradiometric assays to measure total IgA and IgA subclass levels in biological fluids, which take into account the problem that polymeric forms are differently recognized in immunoassays. Sera from subjects totally deficient in one of the IgA subclasses allowed us to ensure the specificity of the subclass assays and to define the proportions of IgA1 (84%) and IgA2 (16%) in the normal pooled serum (from 30 blood donors) used as standard. With purified milk 11-S secretory IgA1 and 11-S secretory IgA2, we determined a correction factor for the corresponding polymeric forms using, respectively, monomeric IgA1 and monomeric IgA2 from pooled serum as standards. With the monoclonal antibodies used, purified 11-S secretory IgA1 was similarly recognized by both the total IgA assay and the IgA1 assay; both total IgA and IgA1 concentrations were underestimated compared with monomeric IgA or monomeric IgA1. In contrast, 11-S secretory IgA2 was better recognized by the IgA2 assay than by the total IgA assay and the values were thus overestimates. Considering this problem of recognition, we fractionated saliva and lung secretions by sucrose density gradient ultracentrifugation before measuring their IgA1 and IgA2 levels.
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Affiliation(s)
- S Depelchin
- Experimental Medicine Unit, Catholic University of Louvain, Brussels, Belgium
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7
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Dugoujon JM, Guitard E, Senegas MT, Grenand P, Bois E. Gm and Km allotypes in Wayampi, Wayana and Emerillon Indians from French Guiana. Ann Hum Biol 1994; 21:335-45. [PMID: 8080235 DOI: 10.1080/03014469400003342] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have studied 506 Amerindians from three French Guiana groups: 194 Wayampi, living in Trois-Sauts, and 100 in the Camopi area; 47 Emerillon also living in the Camopi area and 165 Wayana on the Litani and Maroni rivers. All samples were tested for G1m(1,2,3,17), G3m(5,6,10,11,13,14,15,16,21,24,28) and Km(1) by the classical method of hemaglutination inhibition. The phenotype and haplotype distributions are presented and have been subjected to factorial correspondence analysis. Two Gm haplotypes are common: Gm1,17;21,28, and Gm1,2,17;21,28, but with an important variation in frequency. A rare haplotype, probably the result of a genetic anomaly: Gm1,17;21R,28, is frequent in the Emerillon (17%). These populations show no evidence of Black or Caucasian admixtures.
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Affiliation(s)
- J M Dugoujon
- Centre de Recherches sur le Polymorphisme Génétique des populations humaines, Toulouse, France
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8
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Olsson PG, Rabbani H, Hammarström L, Smith CI. Novel human immunoglobulin heavy chain constant region gene deletion haplotypes characterized by pulsed-field electrophoresis. Clin Exp Immunol 1993; 94:84-90. [PMID: 8403523 PMCID: PMC1534385 DOI: 10.1111/j.1365-2249.1993.tb05982.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Fifteen patients with selective IgG1 deficiency were screened for immunoglobulin H chain C region locus (IGHC) gene deletions and three deletion haplotypes were found: del G1, del G1-G4 and del G4. These haplotypes, together with four deletion haplotypes described by us previously (del G1 (NY), del G1 (VIT) del G1-G2 (NY) and del G2-G4 (HJE)), were further characterized using pulsed-field gel electrophoresis (PFGE) to determine the physical extent of the deletions. The MluI fragment sizes confirmed the deletions, although the deduced sizes of the most extensive deletions indicated that material had been inserted into the locus.
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Affiliation(s)
- P G Olsson
- Centre for BioTechnology, NOVUM Karolinska Institute, Huddinge, Sweden
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9
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Bottaro A, Gallina R, Brusco A, Cariota U, Boccazzi C, Barilaro MR, Plebani A, Ugazio AG, van Leeuwen AM, DeLange GG. Familial clustering of IGHC deletions and duplications: functional and molecular analysis. Immunogenetics 1993; 37:356-63. [PMID: 8428768 DOI: 10.1007/bf00216800] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The human immunoglobulin heavy chain constant region locus (IGHC) comprises nine genes and two pseudogenes clustered in a 350 kilobase (kb) region on chromosome 14q32. Several IGHC haplotypes with single or multiple gene deletions and duplications have been characterized. The most likely mechanism accounting for these unusual haplotypes is the unequal crossing-over between homologous regions within the locus. Here we report the analysis of an unusual case of familial clustering of deletions/duplications. In the two branches of the BON family, three duplicated and two deleted haplotypes, all probably independent in origin, have been characterized. The structure of the haplotypes, one of which is described here for the first time, supports the hypothesis of homologous unequal crossing-over as the origin of recombinant haplotypes. The analysis of serological markers in a subject carrying one deleted and one duplicated haplotype allowed us the first direct inferences concerning the functions of the duplicated IGHC haplotypes.
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Affiliation(s)
- A Bottaro
- Dipartimento di Genetica, Biologia e Chimica medica, Torino, Italy
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10
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Gallina R, Bottaro A, Boccazzi C, DeLange G, Danese P, Mazzola G, Amoroso A, DeMarchi M, Carbonara AO. The genetics of IgG4 deficiency: role of the immunoglobulin heavy chain constant region and HLA loci. Eur J Immunol 1992; 22:227-33. [PMID: 1346112 DOI: 10.1002/eji.1830220133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
IgG4 deficiency is very common (1/400 in the Italian population) and provides a good model for analyzing the genetic factors involved in Ig subclass deficiencies. We have previously reported an association between some immunoglobulin heavy chain constant region (IGHC) polymorphisms and the IgG4 deficiency. The associated polymorphisms spanned the region between the GP and the G4 genes. A larger sample composed of 50 healthy blood donors with IgG4 deficiency (less than 0.001 g/l IgG4), not carrying homozygous gene deletions, together with 82 first-degree relatives is now examined. The results confirmed the association of the deficiency with IGHC polymorphisms, and detected a new association with the HLA-D locus with a strong additive effect between the two systems. However, despite these associations and a highly significant risk for IgG4 deficiency within families, close linkage with either IGHC or HLA loci was not apparent by the affected sib pair method. These findings suggest that several concomitant, possibly cooperating, genetic factors may be involved in IgG4 deficiency.
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Affiliation(s)
- R Gallina
- Dipartimento di Genetica, Biologia e Chimica medica, Torino, Italy
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11
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van Dongen JJ, Wolvers-Tettero IL. Analysis of immunoglobulin and T cell receptor genes. Part I: Basic and technical aspects. Clin Chim Acta 1991; 198:1-91. [PMID: 1863985 DOI: 10.1016/0009-8981(91)90246-9] [Citation(s) in RCA: 169] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- J J van Dongen
- Department of Immunology, University Hospital Dijkzigt/Erasmus University, Rotterdam, The Netherlands
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12
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Cottier H, Kraft R, Meister F. Primary immunodeficiency syndromes and their manifestations in lymph nodes. CURRENT TOPICS IN PATHOLOGY. ERGEBNISSE DER PATHOLOGIE 1991; 84 ( Pt 2):81-155. [PMID: 2044412 DOI: 10.1007/978-3-642-75522-4_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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13
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Bottaro A, Cariota U, de Lange GG, DeMarchi M, Gallina R, Oliviero S, Vlug A, Carbonara AO. Multiple levels of analysis of an IGHG4 gene deletion. Hum Genet 1990; 86:191-7. [PMID: 2125021 DOI: 10.1007/bf00197704] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Human immunoglobulin heavy chain constant region (IGHC) genes constitute a typical multigene family, usually comprising eleven genes on the telomere of chromosome 14 (14q32). In this region, deleted and duplicated haplotypes have been reported to exist with considerable frequency. Their origin is the result of either unequal crossing-over or looping out excision. In this paper, we report the characterization of a new type of deletion, involving the IGHG4 gene, in a subject who also carries a larger deletion of a previously described type on the second chromosome. Employment of several methods (polymerase chain reaction, standard Southern blot, pulsed field gel electrophoresis, serological techniques) to analyze these deleted haplotypes has resulted in a level of accuracy in their characterization that has not been achieved in previous cases. The site of recombination responsible for the IGHG4 deletion was restricted to a 2.5-kb region 3' of the G4 gene; this rules out any possible involvement of the S regions in the recombination process. The usefulness of the various techniques in the characterization of the deletions is also discussed, together with possible future applications in the field.
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Affiliation(s)
- A Bottaro
- Dipartimento di Genetica, Biologia e Chimica Medica, Centro CNR Immunogenetica ed Istocompatibilità, Turin, Italy
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14
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Walter MA, Chambers CA, Zimmerman B, Cox DW. A multigene deletion in the immunoglobulin heavy chain region in a highly atopic individual. Hum Genet 1990; 85:643-7. [PMID: 2121640 DOI: 10.1007/bf00193590] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Highly atopic individuals, with marked allergy, have extremely elevated total plasma IgE levels. To determine if atopy could be associated with structural alterations involving the IGHE gene of the immunoglobulin heavy chain constant region, the genomic DNA from five atopic individuals was examined. We describe here the identification of a deletion of approximately 120kb, including the IGHA1, IGHGP, IGHG2, AGHG4, and IGHE genes of the IGH constant region, in one atopic patient. This deletion arose de novo from a maternally derived chromosome. The deletion, although apparently not the primary cause of the atopic phenotype of this patient, could be indirectly responsible for the phenotype by exposing aberrant immunoglobulin-regulating elements within the paternally derived IGH constant region.
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Affiliation(s)
- M A Walter
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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15
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Bottaro A, DeMarchi M, DeLange GG, Boccazzi C, Fubini L, Borra C, Cappello N, Carbonara AO. Human IGHC locus restriction fragment length polymorphisms in IgG4 deficiency: evidence for a structural IGHC defect. Eur J Immunol 1989; 19:2159-62. [PMID: 2574682 DOI: 10.1002/eji.1830191128] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In man, IgG4 is the least abundant of the four IgG subclasses, and its serum levels vary considerably from one subject to another. Its deficiency has been thought to lead to recurrent infections; nevertheless, it is also commonly found in healthy individuals (1/400 in the Italian population). In 39 subjects with IgG4 serum levels less than 1 microgram/ml, we used 4 different probes (described in the accompanying study, Bottaro et al., Eur. J. Immunol. 1989. 19: 2151) to examine 13 loci within the IGHC region and analyzed the RFLP for 7 of them. No aberrant restriction patterns were identified in any of the subjects, showing the absence of major IGHC structural alterations. The allele frequency of some loci, however, was significantly different from that of a control group of 95 random subjects. This variation was shown to depend on a selective increase in the number of homozygotes for the associated alleles, that reached significant levels for the IGHGP, G2, PG2, PG4 and SG4 loci, but not for SG1 and A2T. The highest value was reached for alleles in the PG4 region, just 5' of SG4. These data indicate that a minor structural IGHC defect is probably the cause of a significant fraction of IgG4 deficiencies. Moreover, the different association levels of the PG4 and SG4 regions suggest that this defect is likely to lie in an upstream regulatory region rather than in the structural G4 gene.
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Affiliation(s)
- A Bottaro
- Dipartimento di Genetica, Biologia e Chimica Medica, Università di Torino, Italy
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16
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Bottaro A, Gallina R, DeMarchi M, Carbonara AO. Genetic analysis of new restriction fragment length polymorphisms (RFLP) in the human IgH constant gene locus. Eur J Immunol 1989; 19:2151-7. [PMID: 2574681 DOI: 10.1002/eji.1830191127] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The human immunoglobulin heavy chain constant gene locus (IGHC) is polymorphic at both the protein (Gm and A2m allotypes) and the DNA level [RFLP for the gamma genes (IGHG), the switch mu region (IGHSM) and the switch alpha regions (IGHSA)]. The polymorphisms have been a valuable tool for assessment of the IGHC locus organization and a variety of population genetics and immunological investigations. In this study three new probes, identifying regions related to the IGHG (IGHPG and IGHSG) or IGHA (IGHAT) genes, have been employed to describe 11 different loci, 6 of which were polymorphic. Most of the polymorphisms are probably due to short insertions/deletions, particularly the SG regions, due to their repetitive structure. Ten loci were assigned to the IGHC region on the basis of known restriction maps, deletion mapping and association with mapped RFLP; the 11th, despite a striking sequence similarity with the IGHPG regions, could not be assigned to any known IGHC subregion. Analysis of these and previously known IGHG RFLP in a sample of 65 unrelated subjects plus 15 families allowed us to draw a genetic map, with particularly high resolution in the GP-G2-G4 genes region, revealing a marked discontinuity in the linkage disequilibrium values between pairs of adjacent loci.
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Affiliation(s)
- A Bottaro
- Dipartimento di Genetica, Biologia e Chimica medica, Università di Torino, Italy
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17
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Keyeux G, Lefranc G, Lefranc MP. A multigene deletion in the human IGH constant region locus involves highly homologous hot spots of recombination. Genomics 1989; 5:431-41. [PMID: 2613231 DOI: 10.1016/0888-7543(89)90006-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A simultaneous absence of the IgG1, IgG2, IgG4, and IgA1 immunoglobulins (Ig) was unambiguously demonstrated in six healthy individuals of two different families (family HASS and family TOU). These individuals were shown to be homozygous for a large deletion in the immunoglobulin heavy chain constant region locus. This deletion, which encompasses the G1-EP1-A1-GP-G2-G4 genes, allowed us to predict an order for the IgCH genes and to localize GP between A1 and G2. In this paper, we study the deletion-recombination point in the IGH locus of individual EZZ from the TOU family. We show that the distance between the G3 and the E genes on the EZZ recombinant chromosome is 24.7 kb and that the multigene deletion in the IgCH locus involves two highly homologous regions (hsg3 and hsg4) which are hot spots of recombination, outside of the switch sequences.
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Affiliation(s)
- G Keyeux
- Laboratoire d'Immunogénétique Moléculaire, URA CNRS 199, Université des Sciences et Techniques du Languedoc, Montpellier, France
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18
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Bottaro A, de Marchi M, Migone N, Carbonara AO. Pulsed-field gel analysis of human immunoglobulin heavy-chain constant region gene deletions reveals the extent of unmapped regions within the locus. Genomics 1989; 4:505-8. [PMID: 2501213 DOI: 10.1016/0888-7543(89)90273-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The human immunoglobulin heavy-chain constant region gene locus is organized in three main gene groups, the physical distances of which are unknown. Different types of gene deletions, originated by unequal crossingover, have been found to encompass one or more genes in the locus. We have analyzed some of these deletions by means of pulsed-field gel electrophoresis, which allows resolution of large DNA fragments. By identifying a fragment containing two of the main gene groups and by observing the size reduction of this fragment in subjects with deletions, we were able to estimate the distance between the two groups and better locate the pseudogene in-between.
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Affiliation(s)
- A Bottaro
- Dipartimento di Genetica, Biologia e Chimica Medica, Università di Torino, Turin, Italy
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