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Biomedical subjects

S Rogde

Publications and source records attributed to S Rogde.

11 recordsLinked to original sources

The gene encoding human transmembrane secretory component (locus PIGR) is linked to D1S58 on chromosome 1.

The human transmembrane secretory component (SC or poly-Ig receptor, PIGR) is expressed basolaterally on glandular epithelial cells and is responsible for the external translocation of polymeric IgA and IgM. SC is hence a key molecule in antibody protection of mucosal surfaces. The human SC gene (locus PIGR) is located on chromosome 1 (1q31-q41). Here we present the first genetic linkage study of PIGR versus syntenic markers, including D1S58 and F13B, which have been previously regionalized to 1q31-q32 and 1q31-q32.1, respectively. We found that PIGR is closely linked to D1S58 (lods + 5.06 at theta max = 0.06, without sex difference). PIGR versus F13B showed + 1.46 at theta max = 0.25 for both sexes combined. A recombination of 0.06 between F13B and D1S58 (lods + 2.24) was in contrast to a previously published study giving theta max = 0.22 (lods + 3.9), the combined lods being 5.6 at theta max = 0.20. The progeny of a triply heterozygotic female indicated that PIGR is the flanking locus, therefore suggesting a cen-F13B-D1S58-PIGR-qter gene sequence on human chromosome 1. Only negative lod scores to RH, C8@, and PGM1 on 1p, and FY on proximal 1q, were found. Current combined Norwegian allele frequencies were estimated for PIGR to be A1 = 0.63, A2 = 0.37 (370 chromosomes), and for D1S58 to be A1 = 0.44, A2 = 0.56 (218 chromosomes).

Chromosome Mapping

Linkage and association studies with C8A and C8B RFLPs on chromosome 1.

Linkage relations for the C8A and C8B BamHI RFLPs have been investigated. A peak lod score of 4.52 at recombination fraction zero was obtained between the two C8 genes. Combined with our previously obtained linkage data (Rogde et al. 1986) the maximum lod score is 7.53 at recombination fraction zero. The compiled C8-PGM1 linkage data from this and the previous study gave a maximum lod score of 22.02 at recombination fraction 0.11 (0.07-0.16) with no sex difference. A chromosome 1p reference marker, D1S57, has been applied in this linkage study. A maximum lod score of 5.06 between the C8 cluster and D1S57 at theta = 0.18 (0.11-0.28) was recorded. The linkage analyses and triply informative families gave evidence that the C8 loci are situated about halfway between PGM1 and D1S57 on the short arm of chromosome 1. There was no evidence of allelic association between the C8A and C8B BamHI RFLPs in 62 unrelated haplotypes.

Chromosome Mapping

C8 reference typing report and nomenclature recommendation.

Using two different typing techniques (i.e. polyacrylamide gel isoelectric focusing (PAGIF) with Western blot and SDS-polyacrylamide gel electrophoresis of precipitated C8 under nonreducing conditions with Western blot), the following observations were made during the reference typing for C81 (C8A). The Japanese variant A1J is probably identical with A1Cauc, whereas B1J is definitely different from B1Cauc and could therefore provisionally be named HB3'. Variant 'A2' from Japan is focused in an intermediate position, but different from M1 and could be named 'M2'. Both variants possess normal A subunits. B2 from Japan is clearly different from B1Cauc and should retain its designation. In PAGIF, its subunit has a position more anodal than A. Summarizing these results, more information is needed before a final nomenclature can be proposed.

Blotting, Western

Genetic aspects of complement component C8 in Norwegian meningococcal disease patients.

Sera from 85 consecutive systemic meningococcal disease patients and 203 matched control individuals were C8 typed. In the patient group, one C8B deficient individual was discovered; none in the control group. No case of C8A deficiency was encountered. The material was collected during a period of epidemic meningococcal disease in Norway, mainly due to group B organisms. C8A and C8B phenotype distributions were not significantly different in the two groups. This indicates that no particular C8 type (apart from deficiency) predisposes for meningococcal disease. Neither is there any evidence of over-representation of heterozygous deficiency among meningitis patients. The C8B deficient individual and his family were studied. Tests for haemolytic complement were normal in all members except for the proband. Electrophoretic C8 patterns seemed to be slightly weaker in the heterozygously C8B deficient individuals than in persons with 2 normal C8B genes. DNA from the family members were studied with regard to a restriction fragment length polymorphism (RFLP) for the C8B gene. All exhibited the same pattern, indicating that the C8B deficiency is not due to a major deletion in the C8B gene.

Complement C8

C8A and C8B polymorphisms in Norwegians and Norwegian lapps.

C8 inheritance patterns in 364 mother-child pairs formed the basis for evaluation of the existence of silent alleles (null alleles) in the genes determining the two known polymorphic C8 systems. While evidence for such alleles was not found in C8A (alpha-gamma complex), two observations of null allele segregation in C8B (beta chain) indicate a C8BQ*0 allele frequency of about 0.07. Two population samples comprising 150 Lappish and 1,264 non-Lappish Norwegians were examined for phenotype distributions in C8A and C8B. The phenotype distributions were mainly in accordance with the expected Hardy-Weinberg distribution. The results for C8A indicated simple, codominant inheritance of two frequent and several rare alleles. Allele frequencies were similar in the two populations. The C8A B gene frequency in Norwegians was significantly lower than that in FRG and higher than that in Negroes. C8B allele frequencies were also calculated from gene counts in the population material, but with due corrections for the C8BQ*0 frequency observed in the mother-child material.

Alleles

The terminal complement complex in sera deficient in the eighth component of complement (C8).

The terminal complement complex (TCC) was quantified in sera from patients with a genetic deficiency of C8 alpha-gamma or C8 beta. The individual sera contained only trace amounts of TCC compared with a normal serum pool. The content of TCC increased after mixing the two sera, which was consistent with reconstitution of C8 activity. Only a moderate increase in TCC was obtained after zymosan activation of the individual sera, whereas activation of the mixture resulted in high amounts of TCC. C8 was demonstrated in the TCC of both deficient sera. These results may indicate that functional C8 is present in trace amounts despite the genetic deficiency, and that the terminal pathway may function to some extent although not enough to be detectable in less sensitive assays.

Antibodies, Monoclonal

The C8A and C8B loci are closely linked on chromosome 1.

Close linkage was demonstrated between the loci governing the polymorphisms of complement component C8 alpha-gamma (C8A) and beta (C8B). Both C8 loci were linked to the chromosome 1 marker loci PGM1 and Rh. The distance between the two C8 loci and PGM1 appeared identical in males and females. A female/male ratio of 1.6 was observed between the two C8 loci and Rh. No evidence for linkage between the C8 loci and Fy was found. Preliminary results of this study were presented at the Eighth International Workshop on Human Gene Mapping, Helsinki, August 1985 (Rogde et al. 1985b).

Chromosomes, Human, Pair 1

Clivus epidural hematoma: a case report.

An acute traumatic epidural hematoma extending from the odontoid process to the dorsum sella is described. The mechanism for the formation of an extradural hematoma in this unusual location seems to be related to age and a severe hyperflexion injury.

Brain

Genetic polymorphism of complement component C8.

Extensive genetic polymorphism of complement component C8 was demonstrated by isoelectric focusing of serum or plasma samples followed by immunoblotting procedures. Using these methods, we could detect both alpha-gamma (C81) and beta (C82) chain polymorphisms in the same gel. Two-dimensional (2D) electrophoresis of C8 immunoprecipitates was used to obtain further information of the C8 patterns. Evidence was obtained that the C81 polymorphism resides in the structural gene of the C8 alpha chain. Both C8 systems show autosomal, chiefly codominant inheritance, and the distribution of phenotypes agrees with the Hardy-Weinberg equilibrium. Our findings suggest at least five different alleles in the C81 system; the gene frequencies of the two most common ones, C81*A and C81*B being 0.59 and 0.39, respectively. In C82 we found evidence for at least three codominant alleles, the gene frequencies for the two most common ones, C82*B and C82*A being 0.94 and 0.05, respectively. In addition, family studies disclosed the existence of a null allele, C82*Q0.

Alleles