Distribution of the group specific (Gc) serum component in the populations of the Markham Valley, New Guinea

The distribution of the Gc phenotypes was determined by immunoelectrophoresis amongst 486 inhabitants of nine villages of the Markham River Valley of New Guinea. The overall gene frequencies were Gc¹, 0.538; Gc², 0.351; Gc^Aborigine, 0.112. Gc^Aborigine occurred in all the villages, its frequency ranging from 0.041 to 0.187. The Gc² gene frequency also varied widely ranging from 0.167 to 0.491. No correlation could be found between altitude and the Gc distribution and there was an overlap in the gene frequencies between the Austronesian and non-Austronesian-speaking villages.     

A faster migrating Gc-variant: Gc Darmstadt

Summary In three members of a family from Darmstadt (Germany) a faster migrating Gc variant has been observed. The variant phenotypes have been examined by routine immunoelectrophoresis (Fig. 1), by immunoelectrophoresis with prolonged separation times and with Gc-monospecific antisera (Fig. 2), by polyacrylamide gel electrophoresis (Fig. 3), and by antigen-antibody crossed electrophoresis (Fig. 4). By antigen-antibody crossed electrophoresis the new Gc variant was clearly distinguishable from the Gc Aborigine and from the Gc Chippewa variant. The variant was named Gc Darmstadt (Gc D). Gc Darmstadt has an electrophoretic migration rate intermediate between Gc Ab and Gc 1. In two sibs the type Gc D-2 was observed, the daughter of one of these sibs had the type Gc D-1. The analysis of several members of this family provided only limited information on the mode of inheritance of Gc Darmstadt (Fig. 5). Gc Darmstadt appears to be determined by a gene Gc^D which may be allelic to Gc¹ and Gc².

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Zusammenfassung Bei drei Angehörigen einer Familie aus Darmstadt (Deutschland) wurde eine schneller wandernde Gc-Variante beobachtet. Die neue Variante, die eindeutig von Gc Aborigine und Gc Chippewa unterschieden werden kann, wurde Gc Darmstadt (Gc D) genannt. Bei elektrophoretischer Auftrennung liegt Gc Darmstadt zwischen Gc Ab und Gc 1. Gc Darmstadt ist sehr wahrscheinluch durch ein Gen Gc^D bedingt, das ein Allel zu Gc¹ und Gc² ist.

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Supported by U.S.-PHS Grant AM 11796 and aided by a grant from the Deutsche Forschungsgemeinschaft, Bad Godesberg.     

Serum protein polymorphisms in a village community from the Gambia,West Africa (Hp,Tf, and Gc)

Summary Serum samples from 857 inhabitants of the village of Keneba, The Gambia, West Africa, were examined by means of polyacrylamide gel electrophoresis. In 203 cases no haptoglobin could be detected, whilst in the remaining 654 samples the three common haptoglobin phenotypes were found with gene frequencies of 0.651 (Hp¹) and 0.349 (Hp²). The D₁ transferrin variant gene was found with a frequency of 0.025. In the serum Gc system the fast variant Gc-Ab was detected, the gene frequencies being: Gc¹, 0.943; Gc², 0.044; and Gc^Ab, 0.013.     

Human transferrin (Tf) and group-specific component (Gc) subtypes in Tunisia

Summary Simultaneous subtyping of two genetic markers—group-specific component (Gc) and transferrin (Tf)—by electrofocusing enabled us to compute the following gene frequencies for the Tunisian population: Gc ^IS .0.525; Gc ^IF , 0.260; Gc ², 0.215; Tf ^CI , 0.770; Tf ^C2 , 0.215; Tf ^D1 , 0.015.The frequencies of Tf ^D , Tf ^C2 , and Gc ¹ are higher than those found in Caucasoid populations and can be explained by Negroid contribution. A selective advantage related to the metabolic role of this vitamin D-binding protein does not seem very likely for any particular Gc type or subtype. It is postulated that the differences in the frequencies of the Gc alleles might be related to selective advantage for genes belonging to other genetic systems originally closely linked to either Gc ¹ or to Gc ² alleles.This work was supported in part by the Faculté de Pharmacie et de Médecine Dentaire of Monastir and by a grant from the Ambassade de France in Tunisia     

Gc types in one Indian group and one Mestizo Mexican group

Summary The distribution of Gc types was investigated in an Indian group residing in Cuetzalan, Puebla, and in a Mestizo group from Mexico City. Gc¹ and Gc² gene frequencies were 0.862 and 0.138 in Cuetzalan, and 0.858 and 0.142 in Mexico City. These figures are similar to those obtained by other authors in one Northeastern Mexican City. A literature review showed that there appears to be a pattern of high Gc²-frequency in most Brazilian Indians (above 0.3) in contrast to a low frequency (below 0.2) in most other Amerindian groups studied.     

The distribution of Gc subtypes among the Mongoloid populations

The polymorphism of Gc (group-specific components) has been investigated for a series of 3,160 individual samples from 11 Mongoloid populations in Asia and North and South America by isoelectric focusing on polyacrylamide gels. The samples fall into six Gc phenotypes which can be explained by the three common alleles, Gc^1F, Gc^1S, and Gc², together with several variant phenotypes explained as the heterozygotes for the three common alleles. The distribution of Gc^1F suballele appears to be considerably different from population to population among Mongoloids, ranging from 0.105 (Machiguenga Indans, Peru) to 0.609 (Kadazan, Borneo). A clear geographic cline from Southeast Asia into South America in Gc^1F allele was observed in the populations. In general, Gc^1F allele frequencies are lower in European populations and higher in African populations. The range of variability in the Gc^1F values observed among the Asiatic populations is between the Africans and the Europeans.     

Group-specific component (Gc) subtypes in the Chinese population of Hong Kong

Summary The distribution of Gc subtypes in a sample of the Chinese population of Hong Kong was studied using isoelectric focusing followed by immunofixation. A sensitive modification of this technique is described. Nine distinct phenotypes were observed which appear to result from the three common alleles Gc ^IF, Gc ^IS, and Gc ², which are found in most populations. The respective gene frequencies were 0.494, 0.258, and 0.247. In addition, two rare phenotypes were observed which appear to be due to a rare allele tentatively identified as Gc ^2G2.     

Analysis of the Gc polymorphism in human populations by isoelectrofocusing on polyacrylamide gels. Demonstration of subtypes of the Gc1 allele and of additional Gc variants

Summary For the study of the group-specific component (Gc) system, serum samples were examined by polyacrylamide gel electrophoresis and by a newly developed immunofixation isoelectrofocusing procedure. Thereby, a greater extent of polymorphic variation was revealed than was known previously. The allele Gc¹ could be subdivided into the alleles Gc^1F and Gc^1S. The distribution of Gc¹ subtypes was very different in three populations (Pygmies, Amerindians, and Pyreneans) examined. New variants of the Gc¹ and Gc² genes were also described in the Amerindian and in the Pygmy population, respectively.     

Die Verteilung der Gc-Phänotypen und Gc-Allele bei einigen Krankheiten (Diabetes mellitus,Leberparenchymschaden, Psoriasis vulgaris)

Zusammenfassung Bei 239 Probanden mit Diabetes mellitus, 213 Leberkranken—bes. Patienten mit akuter und chronischer Hepatitis sowie Lebercirrhosen—und 203 Kranken mit Psoriasis vulgaris wurden die Gc-Phänotypen bestimmt und mit der Gc-Typenverteilung bei 1733 gesunden Kontrollpersonen verglichen. Die Frequenz für das Allel Gc¹ beim Diabetes mellitus liegt mit 0,7490 sowie bei den Leberkrankheiten mit 0,7371 höher, bei der Psoriasis vulgaris mit 0,6749 niedriger als bei der gesunden Kontrollgruppe mit Gc¹ 0,7185. Der Unterschied im Vergleich der Diabetiker sowie der Leberkranken mit den Gesunden ist jedoch nicht signifikant. In der Gruppe mit Psoriasis vulgaris dagegen kommt der Phänotyp Gc2-1 signifikant häufiger vor als der Typ 1–1, allerdings ist diese Stichprobe in sich möglicherweise nicht hinreichend homogen.

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The frequency of the three Gc-phenotypes has been determined in 239 propositi with diabetes mellitus,213 patients with liver diseases—especially acute and chronic hepatitis as well as liver cirrhosis—and 203 persons with psoriasis vulgaris. The distribution in these diseases is compared with 1733 serum samples of healthy inhabitants of South-Niedersachsen with a Gc¹ frequency of 0,7185. The frequency of the gene Gc¹ in diabetes mellitus is 0,7490, in liver diseases 0,7371 and in psoriasis vulgaris 0,6749. These differences are statistically not significant in diabetes and in liver diseases. A significant difference has been found in psoriasis vulgaris between the both phenotypes Gc 1–1 and Gc 2-1 (X ²=10,7164, p(m=1)0,001). It may, however, be discussed wether this sample has a sufficient homogeneity.

     

Gc subtypes in the middle east: Report on an Arab Moslem population from Israel

Gc subtypes were determined by isoelectrofocusing and immunofixation on 342 blood samples from an Arab Moslem population in Israel. Observed allele frequencies were: Gc^1F 0.2120, Gc^1S 0.6023, and Gc² 0.1857. Those are similar to formerly reported frequency data for other Middle Eastern populations. A discriminant analysis, performed on data from 35 populations, resulted in a satisfactory classification of population groups related through geographic and racial origin.     

Sunshine and the geographical distribution of the alleles of the Gc system of plasma proteins

Summary Following the discovery by Daiger et al. (1975) that the Gc proteins of human plasma act as the carriers of vitamin D, the authors have plotted on a world map all available data on the frequency of the allele Gc ², and compared the distribution with that of sunlight. With some exceptions high frequencies of Gc ² correspond to low levels of sunlight and vice versa. Similar comparisons within Ireland show no such relation. The results are discussed in relation to natural selection and the incidence of rickets, due to vitamin D deficiency.     

Gc subtyping in Malaysians and in Indonesians from North Sumatra

Summary Malays, Chinese and Indians from peninsular Malaysia; Ibans and Bidayuh from Sarawak state, Northern Borneo; and Bataks, Minangkabau and Javanese from North Sumatra, Indonesia, were subtyped for Gc (group-specific component) by polyacrylamide gel isoelectric focusing. All eight populations investigated were found to be polymorphic for three common alleles, Gc^IF, Gc^IS and Gc².     

Die Gc-Erbmerkmale im Serum der anthropoiden Affen

Zusammenfassung Es wurden die Seren 33 anthropoider Affen (Pan 12, Gorilla 6, Pongo 11, Symphalangus 4) mit der Agargel-Immunoelektrophorese auf das Vorkommen von group specific components untersucht.Bei allen anthropoiden Affen konnten wir Gc-Globuline mit Anti-Human-Gc-Pferdeseren nachweisen. Bei Pongo und bei Gorilla sind die Gc-Phänotypen hominid geprägt. Bei Pongo fanden sich die Gc-Typen Gc 1-1, Gc 2-1 und Gc 2-2, bei Gorilla fand sich der Typ Gc 1-1. Der bei Pan und Symphalangus fefundene Gc-Typ steht außerhalb des Gc-Systems von Homo; er wird vermutlich durch ein eigenes Allel kontrolliert, das wir mit Gc^ape bezeichnen.Mit drei verschiedenen Anti-Human-Gc-Seren erwiesen sich die Gc-Globuline der anthropoiden Affen immunologisch mit denen des Menschen identisch.

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Sera of 33 hominide primates (Pan 12, Gorilla 6, Pongo 11, Symphalangus 4) have been examined for the presence of the group specific components (Gc) by agar-gel immunoelectrophoresis.With the use of anti-human-Gc-horsesera Gc-globulins were demonstrated in all 33 sera of the four hominide primate species. Gc phenotypes of Pongo and of Gorilla were indistinguishable from human Gc phenotypes. In Pongo the types Gc 1-1, Gc 2-1 and Gc 2-2 have been observed, in Gorilla only the type Gc 1-1 has been found. The Gc phenotype in sera of Pan and Symphalangus was found to be different from the Gc phenotypes in Man. This Gc-type is probably determined by a specific Gc allele, for which the notation Gc^ape has been given.With three different anti-human-Gc-sera reaction of immunologic identity has been demonstrated between the human Gc and the Gc of the four hominide primate species.

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Mit 5 Textabbildungen

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Gene conversion accounts for pilin structural changes and for reversible piliation “phase” changes in gonococci

Pilus⁺ wild-type gonococci (Gc) frequently display gene conversion of their expressed complete pilin gene (CPG); a copy of DNA derived from one of the Gc genome's multiple silent partial pilin genes (PPG) is recombinationally-inserted into the CPG's central and 3 portions with formation of a new, chimeric CPG. Expression of that new CPG leads to either 1) retention of pilus⁺ phenotype but change in pilin primary structure/antigenicity, or 2) phase change to pilus^– phenotype capable of reverting. This study utilizes pilus revertants of P^– rp±Gc and P⁺ colony morphotye variants spawned by P⁺⁺ Gc to examine pilin gene conversion in strain MS11_mk Gc in greater detail. Each revertant's and variant's expressed pilin gene's sequence (as pilin mRNA) was defined to learn whether their differences are due to gene conversion by different PPGs, or by varying stretches from the same PPG, or both. Gene conversion by PPG pilS1 copy 2 has been documented in Gc recovered from a human voluteer's urethra previously inoculated with pilus Gc (strain MS11). The pilus⁺ Gc isolated expressed structurally/antigenically distinct pilins.     

Über die Verteilung der Gc-Typen in Südniedersachsen nebst Literaturübersicht über die Allelenhäufigkeit im deutschen Sprachgebiet

Zusammenfassung An den Seren von 1733 Probanden wurden Gc-Bestimmungen vorgenommen. Es fand sich eine Gc¹-Genhäufigkeit von 0,7185 in Südniedersachsen. Diese Häufigkeit liegt etwas unter dem Durchschnitt im deutschen Sprachgebiet (n=15001) mit 0,7277.

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1733 serum samples from inhabitants of South-Niedersachsen have been submitted to Gc type determination. A Gc¹ gene frequency of 0,7185 was found in this material, which is a little less than the average value of 0,7277 (n=15001) in the total region of German language.

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Direktor: Prof. Dr. med. P. E. Becker     

Untersuchungen zur Populationsgenetik von Island,insbesondere der Region Dalasýsla

The authors report the results of a population genetic survey of the Dalasýsla region (West-Iceland). Our sample size includes n=193 male and female individuals of different age. These individuals are partly related. The following blood and serum groups were determined: ABO, MNS, Rh, P; Hp, Gc, Gm, InV, and Lp. In all these systems observed and expected phenotype frequencies are found to be in good agreement. The following gene frequencies turned out: p₁ ^A=.0888, p₂ ^A=.0456, q^B=.0293, r^O=.8363; p^MS=.2256, p^Ms=.4474, p^NS=.0540, p^Ns=.2730; cde=.4123, Cde=.0966, cDe=.0338, CDe=.2984, cDE=.1589; p^P=.4833; Hp¹=.5157, Hp²=.4843; Gc¹=.7340, Gc²=.2660; Gm¹=.1846, Gm^1,2=.1444, Gm¹²=.6710. The frequency of the phenotype InV (1) comes to 17,6%, that of Lp (a+) amounts to 21,6%.In general the Icelandic phenotype and allele frequencies correspond to the European ones, especially to those observed in Northern Europe. In connection with this the authors discuss briefly, to what extent the present day phenotype distributions (especially concerning the ABO system) of Iceland may be interpreted with regard to historical facts and events. It is pointed out that at any rate also selective acting factors should be taken into consideration in order to interpret really the present day distributions. Within Iceland certain inhomogeneities in the phenotype distributions are present. Factors such as small population sizes, geographical isolation, and gene-drift are most likely responsible for this.     

Evolutionary conservation of equine gc alleles and of Mammalian gc/albumin linkage

Ancient origin of the equine vitamin D binding protein (Gc) polymorphism is suggested by the finding of two alleles, Gc^F and Gc^S, in each of three equine subgenera, Equus, Asinus and Hippotigris. The equine Gc and albumin loci are closely linked (lod score = 6). Although no recombinants were observed, the data are not inconsistent with a map distance similar to the 2 centimorgans reported for the human albumin/Gc linkage relationship. Gametic association between the Gc^F and Alb^F alleles appears probable in the American Standardbred horse, perhaps as a result of population structure. Since Gc and albumin are both polymorphic in rodents and possibly other orders, this linkage group will be useful for studies of the evolution of mammalian linkage groups, as well as for a comparison of meiotic recombination frequencies and linkage disequilibria in different species.     

Genotype Distribution of Vitamin D Receptor Polymorphisms among Indonesian Patients with Chronic Hepatitis B

Background:Chronic hepatitis B is a necro-inflammatory of the liver parenchyma caused by hepatitis B virus (HBV) infection leading to liver cirrhosis and hepatocellular carcinoma (HCC). Genetic variants including single nucleotide polymorphisms (SNPs) within genes regulating immune response may contribute to the progression of chronic hepatitis B (CHB) infection. This study aimed to examine the genotype distribution of vitamin D receptor (VDR) polymorphism among patients with CHB infection and to study its association with the development of cirrhosis and hepatoma.Methods:This cross-sectional study analysed 75 CHB patients, consisting of 36 CHB patients without cirrhosis, 25 CHB patients with cirrhosis, and 14 CHB patients with hepatoma. VDR polymorphism was examined using the Amplification Refractory Mutation System Polymerase Chain Reaction (ARMS-PCR) method.Results:Alanine aminotransferase (ALT) and alpha fetoprotein (AFP) levels did not show any significant differences between study groups, but albumin levels in CHB patients with cirrhosis and hepatoma were significantly lower than CHB patients without cirrhosis (p< 0.05). In contrast, the bilirubin levels in CHB patients with cirrhosis was higher than in CHB patients’ cirrhosis. The most common genotypes of VDR polymorphisms were Ff (57.3%), TT (72%), aa (48%) and bb (74.7%) for Fok1, Taq1, Apa1 and Bsm1 respectively. There was no significant different in the genotype distribution of VDR polymorphism between CHB patients without cirrhosis and CHB with cirrhosis or hepatoma. Conclusion:This study suggest that VDR gene polymorphism may not contribute to the progression of CHB infection.Key Words: Cirrhosis, Hepatitis B, Hepatoma, Polymorphism, Vitamin D Receptor     

On the incidence of blood group O and Gm(−1) phenotypes in patients with malignant melanoma

Summary Fifteen polymorphic systems of the blood (ABO, MNSs, Rhesus, P, Kell, Duffy, Kidd, Hp, Gc, Gm, Inv, aP, PGM₁, EsD, and 6-PGD) were examined in 191 unrelated male and female patients suffering from malignant melanoma. These polymorphic systems were compared with the corresponding phenotype and gene frequencies of controls from the same geographical area (Rhineland-Palatinate). The only associations discovered were the ABO and Gm polymorphisms: The incidence of O and Gm(-1) phenotypes in patients is obviously higher than in controls. These observations agree with the findings in other population samples from Germany and Bulgaria.     

Gc (vitamin D binding protein) subtypes in rheumatoid arthritis

Summary Two hundred and six patients with rheumatoid arthritis were examined for their association with the subtypes of Gc (vitamin D binding protein). In patient groups there is 11% excess of individuals with Gc^*2 allele compared to the control group, giving a relative risk of 1.55. This risk increases with the humoral status of the individual. A possible physiological basis between the association of vitamin D binding protein and rheumatoid arthritis is discussed.