Properdin factor B (Bf) polymorphism in Saudi Arabs. High frequency of a 'rare' allele BfS0.7

The distribution of properdin factor B (Bf) phenotypes and the gene frequencies were investigated in 918 Saudi Arabs. A high frequency of the 'rare' allele BFS0.7 was observed BfS0.7 = 0.1514). The frequencies of the common Bf alleles (BfS = 0.5174, BfF = 0.3213) are outside the corresponding ranges of BfS, BfF gene frequencies found in European Caucasoids.     

Genetic polymorphism of C3 in the Veneto population, Italy

The distribution of C3 phenotypes in the population of Veneto was investigated by electrophoresis on agarose gel. In our sample (n = 810) the three common phenotypes C3 SS, C3 FF and C3 FS and a further phenotype, C3 S-VF, were observed. The following gene frequencies could be calculated: C3S = 0.8068, C3F = 0.1926 and C3V = 0.0006. These frequencies have been compared with those found in other populations. The analysis of 21 mother-child pairs was in agreement with an autosomal codominant inheritance.     

Properdin factor B frequencies in four Asian populations

The distribution of Properdin factor B (Bf) phenotypes and their gene frequencies were investigated in four Asian populations (Chinese, Filipino, Thai and Japanese). The frequency of the BfS phenotype in Filipinos (0.717) was significantly lower than that in Chinese (0.900) and Thai (0.889) (p less than 0.01), but not different from the Japanese (0.840). One variant, BfF 0.65 S, was identified in a Japanese subject. Thus, in the Asian populations studied, Bfs frequencies were high and the frequency of variants other than F and S were low.     

Study of five haemogenetic markers (Gc, C3, Bf, Ag, and GALT) in six Indonesian populations and in 12 subgroups of Balinese

In various ethnic groups of the Indonesian archipelago and of Bali, the polymorphisms of the serum proteins Gc globulin (vitamin D-binding protein), C3 (complement component 3), Bf (complement factor B), Ag x,y (lipoprotein allotypes), and of the red cell enzyme system GALT (galactose-1P-uridyltransferase) were analysed. Among the studied proteins, the Gc system was the most informative one for the anthropologist. Besides considerable differences of frequencies of the common alleles Gc*1F, Gc*1S and Gc*2, a number of rare alleles (1A1, 1A3, 1A8, 1A9, 1A12, 1C2, 1C21, 1C24, and 2C8) and some new ones (1C28, 1C29, 1C30, 2C9) were observed. The presence of Gc*1A1 demonstrates the relationship to the Australo-Melanesian populations, but Mongolian variants (1A3, 1A8, 1A9, 1C2) were also encountered. Within the C3 system a very high frequency of the C3*S allele was observed in all populations. The rare alleles C3*F0.55, C3S1, and C3*S0.5 were observed in some groups. A new allele (C3*F0.35) was detected in a Chinese individual and in a nobleman from Bali. The frequency of the Bf*F allele was rather low in general, and the Bf*S0.7 allele was found in three Indonesian individuals only. The Ag*(x) frequencies were rather high, as it is known for Asiatic populations. Variability among subgroups was not very pronounced. The GALT*2 allele (Duarte variant of the enzyme) was observed very rarely; however, it was present in several populations. Enzyme activities could not be determined, and therefore we cannot tell whether the galactosaemia gene (GALT*0) was present or not.     

Bf and C3 complement types in rheumatoid arthritis

Bf and C3 complement types were studied in 100 male and 100 females patients from northern Sweden with erosive rheumatoid arthritis (RA) and compared with population controls. A significantly decreased frequency of the Bf FS phenotype was found particularly in males and in patients with a family history of polyarthritis. Significant Bf associations were also found with a more severe form of RA (functional classes III and IV) and with high titers of the rheumatoid factor. No significant difference with respect to C3 phenotype and gene frequencies was found between RA patients and controls. Thus, the association between RA and C3F found in some previous investigations was not confirmed.     

Human MHC class III genes, Bf and C4. Polymorphism, complotypes and association with MHC class I genes in the Finnish population

Electrophoretically detected genetic polymorphism of human MHC class III genes, factor B (Bf) and complement C4A and C4B, was studied in the Finnish population. Bf alleles were determined in a panel of sera from 70 unrelated individuals. The common Bf alleles, Bf*S and Bf*F, had frequencies of 73% and 26%, respectively. Only in 1 individual was another allele, Bf*F1, detected. The frequencies of the C4A and C4B alleles were based on studies of 254 unrelated individuals. In this panel, five different alleles were detected at the C4A locus and four at the C4B locus. At both loci an allele without a gene product, i.e. a 'null' allele, was observed with high frequency, 11% for C4A 'null' and 17% for C4B 'null'. The association of complotypes to HLA haplotypes was analyzed in 70 chromosomes. The most common combination, defined by class I and class III alleles, was HLA-B7-S31 (13%), followed by HLA-B35-F20 (8.4%) and HLA-B8-S03 (7.1%). Some HLA-B specificities, for example B15, B27 and B40, were associated with a variety of complotypes. The importance of complotyping in HLA genetics is discussed.     

我国瑶、汉、壮、苗、维五个民族补体成份B因子多态性的调查报告

用琼脂糖凝胶高压电泳及免疫固定技术对我国瑶、汉、壮、苗、维五个民族人群的补体B因子(Bf)的多态性进行了检测,结果显示,这五个民族的Bf基因频率均以s型最高,但参差不齐。从高到低的顺序是瑶0.9071,汉0.8727,壮0.8426,苗0.7667,维0.6622。BfF基因频率其次,但也高低不一,从高到低的顺序是维0.2680,苗0.2000,壮0.1343,汉0.1159,瑶0.0929。频率居第三位的是BfSO7,差别显著,维0.0586,苗0.0333,壮0.0232,汉0.0091,瑶0.0000。在罕见型方面,220例份汉族人中发现一例SO45杂合子,222例份维族中检出4例FO65及1例F1杂合子。本文结合我国其他民族及全球大量检测数据进行了一些对比讨论。     

Polymorphic variants of the third component of complement in Graves' disease

We have examined electrophoretic variants of the third complement component (C3) in 294 controls and in 44 patients suffering from Graves' disease, drawn from the Avalon Peninsula of Newfoundland. Two common C3 variants, S and F, account for 99% of the gene frequencies. The S homozygote phenotype was observed in 170 controls and in 27 patients; 18 controls were found to be homozygous for the F allele (3 patients), and the FS phenotype was observed in 103 controls and 14 patients. The phenotypic frequencies did not differ significantly between controls and patients. It is concluded that C3 variants do not distinguish individuals who have Graves' disease.     

Bf and C3 polymorphisms in rheumatoid arthritis

Properdin factor B (Bf) and complement C3 polymorphisms were studied in 225 unrelated rheumatoid arthritis (RA) patients from North-East England. Patients were subdivided on the presence or absence of significant titres of rheumatoid factor and antinuclear factor. No association with the C3 system was detected. For the Bf system, a significant excess of Bf SS and deficiency of Bf FS phenotypes was observed in seropositive RA patients lacking antinuclear antibodies. This finding suggests that auto-antibody-defined subgroups of RA may be genetically heterogeneous with respect to Bf and confirms the status of Bf SS phenotype as a marker for RA susceptibility and/or severity.     

Population genetic data on properdin factor B (Bf) in northern Germany.

Properdin factor B phenotypes were determined in 1,112 unrelated individuals and in 151 mother/child combinations from Northern Germany. Gene frequencies were : F = 0.1960, S= 0.7905, F1 = 0.0072, S1 = 0.0063. The data of the mother/child combinations are in full accordance with the postulated gene model.     

Involvement of interaction between viral VP466 and host tropomyosin proteins in virus infection in shrimp

The C3 component of complement has different roles in kidney disease and its local production in donor kidney may affect allograft function and rejection after organ transplantation. A single base substitution in c3 gene (rs2230199), defines two common allelic variants with different mobility on gel electrophoresis: S (Slow) and F (Fast). In order to evaluate the effect of this polymorphism on acute renal allograft rejection, one hundred samples of donor and recipients were collected and genotyping was done by PCR-RFLP method. The allelic frequencies were: C3S=0.791, C3F=0.209. There was no significant association between recipient's genotype and acute rejection (p value<0.05). No correlation between donor genotype and acute rejection was also present. Patients were divided into four groups, according to the recipient and donor genotypes: SS recipients and FS or FF donor, SS recipient and donor, FF or FS recipient and SS donor and FS or FF recipient and donor. There was no significant difference in rate of acute rejection between groups. Although the results didn't find any association between C3 complement polymorphisms and acute allograft rejection, there was no acute rejection in FS or FF donors and SS recipient group.     

C3 polymorphism in Greece

The polymorphism of the third component of the human complement (C3) was investigated in a sample of 1,055 unrelated healthy individuals from nine different areas of Greece. The estimated gene frequencies were: C3S = 0.786 and C3F = 0.211. Three individuals were found to have rare variant C3 types. The allele frequencies resemble those reported for other Caucasian populations.     

Complement phenotypes in patients with psoriasis

Phenotype frequencies for the complement proteins C4A, C4B, Bf (factor B) and C3 were performed for 49 Caucasian patients with psoriasis. The C4*A6 allele was present in 26.6% of the patients as compared to 5.4% of healthy regional Caucasian controls, p less than 0.001, relative risk = 6.28. The C4*A6 allele is known to be in linkage disequilibrium with the HLA B17 allele and to produce a non-functional gene product when it occurs with the B17 allele. HLA B17 is known to be associated with psoriasis in many Caucasian populations. Additional findings in the present study were a significant reduction in the C4B*2 allele frequency, a non-significant increase in the Bf*F allele frequency and no difference for Bf or C3 phenotype frequencies in the patients with psoriasis as compared to the controls.     

Transferrin C subtype frequencies in the Finnish population

Transferrin (Tf) C subtypes were determined in 419 unrelated adult Finns. The calculated gene frequencies were C1 = 0.738, C2 = 0.097 and C3 = 0.133. The Tf phenotypes in 150 mother-child pairs were in accordance with autosomal codominant inheritance. This material included a rare TfC allele product in three individuals, apparently the same in all cases.     

Paragonimus ohirai: genetic control of tetrazolium oxidase isozymes

The Japanese lung fluke, Paragonimus ohirai, has three electrophoretic variants: F, FS, and S of tetrazolium oxidase (EC 1.15.1.1). Variant flukes were crossed in the laboratory. In both crosses, S X S and F X F, parental phenotypes appeared in all respective F1 progeny. In a cross of F X S, all F1 individuals derived from each parent showed the same phenotype (FS) indicating a heterozygote. On the other hand, from the cross of FS X S, 13 of FS and 11 S were observed from a parent (FS) while 2 FS and 1 S were recovered in three clones from the other parent (S). In the case of a cross between FS X F, a parent (F) produced 9 FS and 18 F clones in the offspring, numbers not significantly different from the expected values of Mendelian inheritance at the 0.01 level. The breeding data indicate that the tetrazolium oxidase isozymes of P. ohirai are controlled by two alleles, ToF and ToS, at a single locus.     

Gc and C3 polymorphisms in Central Sardinia

The distribution of phenotypes and gene frequencies of the group-specific component (Gc) and C3 complement were studied in Central Sardinian sample. The gene frequencies were:Gc1 = 0.733; C3F = 0.237.     

Gc and C3 polymorphisms in South Sardinia

The distribution of phenotypes and gene frequencies of the group-specific component (Gc) and C3 complement were studied in South Sardinia. The gene frequencies were: Gc1 = 0.7346; C3F = 0.1963.     

Distribution of C3 and Bf allotypes in Tuscany (Italy)

The C3 and Bf polymorphisms were studied in 1,000 unrelated Italians. The gene frequencies were calculated and compared with other districts of Italy.     

C3 and C6 complement types in schizophrenia

C3 and C6 complement types were studied in schizophrenic patients and controls. The distributions of the three common C3 types (F, FS and S) among the patients was significantly different from that in the controls (p less than 0.005) and the frequency of the C3F gene was significantly increased (p less than 0.0005) among the patients. There were no significant differences in C6 gene or phenotype frequencies between patient and controls.     

Experimental studies on population genetics of complement 3 (C3) and serum component transferin (Tf) in the population of Northern Bavaria]

Within a population sample concerning 2500 blood donors of Northern Bavaria, the population genetics of the Systems C3 and Tf have been investigated. The calculated gene frequencies are: C3S = 0,789; C3F = 0,2028; C3Var. = 0,0082; TfC = 0,9960; TfVar. = 0,0040. As a "new" variant C3F1,55 has been found.