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.     

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.     

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     

Serumprotein polymorphisms in Iran

Summary The results of a population genetic investigation on Iranians are given and compared to the results obtained on other populations from Southwestern and Southern Asia. Our total material from Iran comprises n=1020 nonrelated male and female individuals of different age. The following serum groups have been typed: Hp, Gc, Gm, and Inv. In general there exist no remarkable age or sex differences in the distribution of phenotypes and alleles (the only exception: sex differences in the distribution of the Gm (7)-phenotype). The regional distribution of phenotypes and alleles yield no marked differences, too, apart from the Invphenotypes, however. For the total material of Iran the following alleles frequencies could be calculated: Hp¹=0.3045, Hp²=0.6595, Gc²=0.3405; Gm¹=0.1780, Gm^1,2=0.0537, Gm^1,5=0.0632, Gm⁵=0.7051. The Gm (7)-phenotype turned out to be 36.6%; the Inv (1)-phenotype amounts to 25.6%. Comparing with other populations, especially Pakistani and Indian samples, some heterogeneity in the distribution of phenotypes and alleles within Southwestern and Southern Asia was to be demonstrated. Some distributional trends of alleles frequencies shall be mentioned here: the increase of Hp², Gc¹, and Gm¹ alleles from West towards East, and in the opposite direction the decrease of Hp¹, Gc², and Gm⁵ alleles. Selective acting forces are supposed to be most important factors for this. D77     

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.     

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.     

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.     

Restriction and persistence of polymorphisms of HLA and other blood genetic traits in the Parakanã Indians of Brazil

Results concerning HLA types and 22 other blood genetic systems are reported for the Parakanã Indians of northern Brazil, a tribe that is notable for the light color and pilosity of some of its members. No clear evidence of Caucasoid admixture was found, but the Parkanã show unusual frequencies in the EsD¹, PGM¹₁, Gc², Cp^B, Fy^a, Di^a, and L^M genetic markers. In addition, the very rare Rh allele r^y is present, as well as what seems to be a new PGM₂ variant. There is very limited heterogeneity in the HLA system. All these distinctive features may have arisen through a combination of founder effects and genetic drift. However, low F_is values, as well as higher mean ages in heterozygous as compared to homozygous persons, suggest that an heterotic effect is counteracting these dispersive forces.     

Intra and intertribal genetic variation within a linguistic group: The Ge-speaking Indians of Brazil

A total of 562 individuals living in four villages of two Brazilian Indian tribes (Cayapo and Krahó) was studied in relation to blood groups ABO, MNSs, P, Rh, Lewis, Duffy, Kidd and Diego; haptoglobin, Gc, acid phosphatase and phosphoglucomutase types. These results were compared with those obtained previously among the Xavante, and the inhabitants of three other Cayapo villages, all of whom speak Ge languages; the ranges in gene frequencies observed in a representative series of South American Indians from all over the continent were also compiled. The Ge Indians are characterized by low frequencies ofR^z, medium frequencies ofR¹,R², R⁰, orr,Jk^a andPGM¹₁, and high frequencies ofGc² andACP^A when compared with other South American tribes. Genetic distance analyses based on six loci indicate that the intratribal variability observed among Cayapo is of the same order of magnitude as those obtained among the Xavante and Krahó, being much less pronounced than those observed among the Yanomama and Makiritare. The intertribal differences within this linguistic group are much less pronounced than those encountered among tribes that speak more differentiated languages.     

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.

     

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.     

Zur Häufigkeit der Serumprotein-Polymorphismen Hp,Gc, Gm,InV und Lp in Griechenland

The authors report the frequencies of Hp-, Gc-, Gm-, InV-, and Lp-phenotypes and alleles in a Greek sample of 218 unrelated adult males and females. The following gene-frequencies were obtained: Hp¹=.2850, Hp²=.7150; Gc¹=.7590, Gc²=.2410; Gm¹=.1555, Gm^1,2=.1015, Gm¹²=.7430. The phenotype InV (1) was found to be 14.6%. Lp (ax)-typing showed 17.0% strong positive individuals, 9.7% weak positive ones, and 73.3% negatives. According to Speiser and Pausch (1965) this may be interpreted as the following phenotypes distribution: Lp (a+x+)=17.0%, Lp(a+x-)=9.7%, and Lp(a-x-)=73.3%. Our data differ somewhat from data obtained by other authors, which seems to indicate heterogeneity in the distribution of at least Hp- and Gm-phenotypes within the Greek population. This is project to further research.     

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.     

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.     

Genetic polymorphism of human urine deoxyribonuclease I

Summary A genetic polymorphism of human urine deoxyribonuclease I (DNase I) has been detected by the technique of polyacrylamide gel isoelectric focusing (IEF-PAGE) followed by immunoblotting with anti-DNase I antibody. Family studies showed that the three common phenotypes —DNASE1 1, 1–2, and 2 — and the other four rare phenotypes — DNASE1 1–3, 2–3, 2–4, and 3–4 — represent homozygosity or heterozygosity for four autosomal codominant alleles, DNASE1 ^* 1, ^* 2, ^* 3, and ^* 4. The frequencies of the DNASE1 ^* 1, DNASE1 ^* 2, DNASE1 ^* 3, and DNASE1 ^* 4 alleles in a studied Japanese population were 0.5453, 0.4396, 0.0117, and 0.0034, respectively.     

Gc (vitamin D binding protein) subtype polymorphism and variants distribution among Saharan,Middle East,and African populations

This article presents the results obtained by electrophoretic analysis of the group specific component polymorphism in more than 1,250 serum samples from populations living in the Sahara, the Middle East, and equatorial Africa. In addition to the alleles Gc^IF and Gc^IS, five variants, including one previously unknown, were found. The distribution of the alleles herein described permits speculation on exchanges and relation among the groups considered. The lowest frequencies of the gene Gc² correspond to regions where sunlight is stronger. There is also a north-south gradient in the Gc^IF gene frequency. This seems to parallel the gradient seen in skin pigmentation.     

Primate red cell enzymes: glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase

Glucose-6-phosphate dehydrogenase (E. C.: 1.1.1.49) phenotypes and 6-phosphogluconate dehydrogenase (E. C.: 1.1.1.44) phenotypes were determined by starch-gel electrophoresis of red cell hemolysates of Galago crassicaudatus subspp., Propithecus verreauxi, Lemur spp., Hapalemur griseus, and Macaca mulatta. A single glucose-6-phosphate dehydrogenase (G6PD) phenotype was found in each species. A single 6-phosphogluconate dehydrogenase (6PGD) phenotype was found in Lemur spp., Hapalemur griseus, and Galago crassicaudatus argentatus. In a group of six Propithecus verreauxi, three 6PGD phenotypes, PGD A, PGD AB, and PGD B, were found. Three phenotypes, PGD A, PGD AB, and PGD B, were found in 38 G. c. crassicaudatus. The three phenotypes in each species are apparently the products of two codominant autosomal alleles, PGD^A and PGD^B. The frequency of PGD^A in G. c. crassicaudatus is 0.263. A population of 260 free-ranging macaques displays a polymorphism at the 6PGD locus. Three phenotypes, PGD A, PGD AB, and PGD B, were found. These also appear to be controlled by two codominant autosomal alleles, PGD^A and PGD^B the frequency of PGD^A = 0.913. Additional analysis of three well-defined troops within the macaque population indicated that there are no significant differences between the troops or within the population at the 6PGD locus.