Human red cell esterase D polymorphism in Denmark, its use in paternity cases and the description of a new phenotype

Red cell esterase D (EsD) phenotypes were determined in a Danish population sample of 3,116 unrelated adults by starch-gel electrophoresis. A new phenotype was discovered, which appeared to be determined by the EsD1 allele and a new allele EsDCph. The gene frequencies observed were EsD1 = 0.9007, EsD2 = 0.0992, EsDCph = 0.0001. Investigation of 1,111 mother-child pairs and 59 families with 157 offspring added further support to the genetic model of two common alleles at an autosomal locus. The applicability of the EsD polymorphism to paternity testing was investigated on 960 cases of disputed paternity. An estimate of the EsD null allele frequency (0.001) in European populations was made on the basis of observations made on 5,864 mother/child combinations and 762 matings with 1,882 offspring. The influence of this allele on the reliability of exclusions of paternity was determined.     

Genetic studies of human apolipoproteins. XX. Genetic polymorphism of apolipoprotein J and its impact on quantitative lipid traits in normolipidemic subjects.

Apolipoprotein J (apo J) is a newly identified member of a growing family of proteins associated with various lipoprotein particles. Apo J is a glycoprotein which exists in the plasma associated with high-density lipoprotein subfractions which also contain apo A-I and cholesteryl ester transfer protein (CETP). We have investigated the possible existence of genetic polymorphism at the apo J structural locus and have evaluated its role in lipid metabolism. By employing isoelectric focusing and immunoblotting techniques, we have screened plasma or serum samples from six population groups: U.S. whites, Amerindians, Eskimos, New Guineans, U.S. blacks, and Nigerian blacks. Apo J revealed a common two-allele polymorphism only in populations with African ancestry and was found to be monomorphic in all other population groups tested. The genetic basis of the two alleles designated--APO J*1 and APO J*2, at a single structural locus, apo J-- was confirmed in a large number of segregating families. In the U.S. blacks, the frequencies of the APO J*1 and APO J*2 alleles were .76 and .24, respectively, and in the Nigerian blacks these values were .72 and .28, respectively. In addition, a single example of a rare allele designated APO J*3 was also encountered in the U.S. black sample. In Nigerian blacks, the apo J polymorphism's impact on seven quantitative lipid traits--total cholesterol, LDL-cholesterol, HDL-cholesterol, HDL3-cholesterol, HDL2-cholesterol, VLDL-cholesterol, and triglycerides--was investigated. No significant impact of the apo J polymorphism was observed for any of these lipid traits.     

Description of a genetic polymorphism of a human proline-rich salivary protein,Pc, and its relationship to other proteins in the salivary protein complex (SPC)

A new polymorphism, Pc, has been identified in human saliva. Two proteins, Pc 1 and Pc 2, are determined by alleles Pc1 and Pc2, respectively, which show autosomal codominant inheritance. No null phenotype has been encountered in 225 randomly collected salivas. The frequencies of the two alleles differ in the Black and White American populations, with Pc1 and Pc2 being 0.670 and 0.330 in the Black (N = 47) and 0.461 and 0.539 in the White (N = 178) populations, respectively. The alleles are in equilibrium in the two populations and segregation analyses (30 families) do not suggest the existence of a null allele in either population. Of seven polymorphic human salivary proteins determined by genes in the salivary protein complex (SPC), Pc phenotypes show association only with Ps phenotypes. Based on that association, our linkage studies, and the biochemical similarities with other SPC proteins, we tentatively conclude that Pc is a member of the SPC, bringing the total number of genes in that group to 13.     

High degree of genetic polymorphism in apolipoprotein(a) associated with plasma lipoprotein(a) levels in Japanese and Chinese populations

We have developed a sensitve, high-resolution method for the analysis of the apolipoprotein(a) [apo(a)] isoforms using sodium dodecyl sulfate (SDS)-agarose/ gradient polyacrylamide gel electrophoresis. In an analysis of the genetic polymorphism of apo(a) isoforms and their relationship with plasma lipoprotein(a) [Lp(a)] levels in Japanese and Chinese, this method identified 25 different apo(a) isoforms and detected one or two apo(a) isoforms in more than 99.5% of the individuals tested. The apparent molecular weights of the apo(a) isoforms ranged from 370 kDa to 950 kDa, and 22 of the 25 different apo(a) isoforns had a higher molecular weight than of apo B-100. Studies on Japanese families confirmed the autosomal codominant segregation of apo(a) isoforms and the existence of a null allele at the apo(a) locus. The observed frequency distribution of apo(a) isoform phenotypes fit the expectations of the Hardy-Weinberg equilibrium in both the Japanese and Chinese populations. Our data indicate the existence of at least 26 alleles, including a null allele, at the apo(a) locus. The frequency distribution patterns of the apo(a) isoform alleles in Japanese and Chinese were similar to each other and also similar to that of apo(a) gene sizes reported in Caucasian American individuals. The average heterozygosity at the apo(a) locus was 92% in Japanese and 93% in Chinese. A highly significant inverse correlation was observed between plasma Lp(a) levels and the size of apo(a) isoforms in both the Japanese (r=-0.677, P=0.0001) and the Chinese (r=-0.703, P=0.0001). A highly skewed distribution of Lp(a) concentrations towards lower levels in the Japanese population may be explained by high frequencies of alleles encoding large apo(a) isoforms and the null allele.     

Apolipoprotein E Polymorphism in Sheep

Using polyacrylamide gel isoelectric focusing followed by immunoblotting with anti-human apolipoprotein E (APO E) antibody, the genetic polymorphism of APO E was determined from desialylated plasma of 554 unrelated adults of four European sheep (Suffolk, Corriedale, Cheviot, and Finnish Landrace) and five Asian local sheep (Bhyanglung, Baruwal, Kagi, Lampuchhre, and Vietnamese). Twenty phenotypes consisting of the homozygous and heterozygous combinations of two APO E variants within the seven variants (E1-E7) detected were identified. Family and population data supported the hypothesis that the phenotypes are controlled by seven codominant alleles, designated APOE1 to APOE7, at a single autosomal locus. The common alleles, APOE4, APOE5, and APOE7 were observed at mean frequencies of 0.5763, 0.1471, and 0.1921 in the European sheep group and 0.4920, 0.1123, and 0.2995 in the Asian local sheep group, respectively.     

The monotony of transferrin and esterase electrophoretic patterns in pirarucu, Arapaima gigas (Schinz, 1822) from Santa Cruz Lake, Tefé River, Amazonas, Brazil

Starch gel electrophoresis was used for examining the transferrin gene locus (Tf) and two esterase gene loci (Est-1 and Est-D1) of a pirarucu (Arapaima gigas) population sample collected from Santa Cruz Lake, Tefé River, Amazonas, Brazil. The Tf locus was tentatively classified as being polymorphic, showing two double-banded patterns (Tf(12) and Tf(22)) of the three theoretically expected ones (Tf(11), Tf(12) and Tf(22)), presumably controlled by two co-dominant alleles, Tf(1) and Tf(2). The monotony detected in pirarucu Tf locus genotypes showing a very high proportion of the double-banded heterozygote pattern Tf(12) (95% of the sampled individuals) may indicate the possibility of their having come from representatives of the same brood begotten by a pair of fish, where a single-banded Tf(11) homozygote pattern male would have crossed with a single-banded Tf(22) homozygote pattern female, or vice versa. One zone of electrophoretic activity was detected in esterase, presumably controlled by a monomorphic Est-1 locus with the fixed allele Est-1(1) where all individuals showed the single-banded Est-1(11) homozygote pattern. Esterase-D also displayed one zone of electrophoretic activity, presumably controlled by a monomorphic Est-D1 locus with a fixed allele Est-D1(1) where all individuals revealed the single-banded Est-D1(11) genotype pattern. The monotony comprised by single-banded genotype patterns in both esterase systems tested may also indicate the possibility of the individuals from the sample examined having come from representatives of the same brood begotten by a pair of fish with both the male and female having the same genotypes.     

Genetic studies of human apolipoproteins. X. The effect of the apolipoprotein E polymorphism on quantitative levels of lipoproteins in Nigerian blacks.

Human apolipoprotein E exhibits genetic polymorphism in all populations examined to date. By isoelectric focusing and immunoblotting, three common alleles have been demonstrated in 365 unrelated Nigerian blacks. Furthermore, the APO E genetic polymorphism's effect on quantitative levels of lipids and lipoproteins has been determined. The respective frequencies of the APO E*2, APO E*3, and APO E*4 alleles are .027, .677, and .296. The effect of APO E polymorphism is significant only on total cholesterol and low-density lipoprotein cholesterol. The average excesses of the APO E*2 allele are to lower total cholesterol and low-density lipoprotein cholesterol by 9.19 mg/dl and 11.11 mg/dl, respectively. The average excesses of the APO E*4 allele are to increase total cholesterol and low-density lipoprotein cholesterol by 5.64 mg/dl and 6.18 mg/dl, respectively. On the basis of the differences in (a) the distribution of APO E allele frequencies between the Nigerians and other populations and (b) dietary lipids, we propose a model that shows that lipid metabolism is influenced by the combined effects of the APO E polymorphism and environmental factors.     

Genetic effect of two APOA repeat polymorphisms (kringle 4 and pentanucleotide repeats) on plasma Lp(a) levels in American Samoans

Elevated plasma lipoprotein(a) [Lp(a)] level has been established as an independent risk factor for atherosclerosis and coronary heart disease. Considerable ethnic group differences in the distribution of plasma Lp(a) levels have raised public health concerns. Recently, we have reported that Samoans have the lowest plasma Lp(a) levels of any population group. In the present investigation, we report the contribution of two apolipoprotein(a) (APOA) polymorphisms, the kringle 4 type 2 (K4) repeat and the pentanucleotide repeat (PNR), in affecting plasma Lp(a) levels in an American Samoan sample (n = 309). The K4 repeats ranged in size from 15 to 40. The common alleles contained repeats ranging from 26 to 36 with allele frequencies between 5.5% to 9.7%, and these accounted for 82% of all alleles. An inverse relationship between K4 repeat number and plasma Lp(a) level was observed for single-banded (r = -0.59, p = 0.0001) and double-banded phenotypes (r = -0.50, p = 0.0001). This polymorphism explained 60% of the variation in plasma Lp(a) level in American Samoans. For the PNR polymorphism, five different repeat alleles and eight different genotypes were identified; the most common allele was eight repeats. The *8 PNR allele was associated with a wide range of K4 repeats, the *9 PNR allele with larger K4 repeats (25-40), and the *10 PNR with smaller K4 repeats (15-24). Analysis of variance (ANOVA) revealed that the PNR polymorphism accounts for 2.1% of the variability in plasma Lp(a) levels in this sample, when the K4 repeat polymorphism was taken into account. Our data show that common polymorphisms in the APOA gene are major determinants of plasma Lp(a) variation in American Samoans.     

Short tandem repeat polymorphism of the D2S1242 locus in a Japanese population

Allele frequencies and sequence characteristics of the D2S1242 short tandem repeat (STR) locus were studied in a Japanese population sample. A total of 10 D2S1242 alleles and 34 genotypes were identified in 273 unrelated Japanese individuals. The five most common alleles detected had frequencies of over 10%. No deviations from Hardy-Weinberg equilibrium were found when the expected allele values were compared with the observed values. Sequence analysis of each allele showed a tetranucleotide polymorphism. Alleles 9 to 14 had different sequence structures than alleles 15 to 19. Allele 18 had a different sequence in the Japanese sample compared to an Austrian sample. The power of discrimination was 0.95. The present results demonstrate that the D2S1242 STR locus is a useful genetic marker in the Japanese population.     

中国维吾尔族人群MSY1(DYF155S1)基因座多态性及其结构特点

应用荧光标记MVR-PCR、Amp-FLP与DNA序列分析技术等检测106例中国维吾尔族人群无关男性个体血纱样品,揭示了中国维吾尔族人群Y特异的小卫星MSY1 (DYF155S1)基因座5′和3′端多态性及其基因结构特点。DYF155S1基因座的多态性表现为3个方面：（1）长度多态性;（2）5′端多态性;（3）3′端多态性。106例无关个体共检出37个不同长度的片段,5′端检出68个类型,3′端检出23个类型。综合这3方面多态性,106例个体间没有相同,其基因多样性（h）超过0.9999。DNA序列分析发现该基因座5′端表现有7种模块结构,3′端有2种模块结构。DYF155S2片段缺失率约为4.7%。MVR-PCR、Amp-FLP与DNA序列分析技术结合起来可以更充分地揭示人群Y染色体特异的小卫星MSY1（DYF155S1）基因座多态性,并提出命名方式,从而为人类遗传学及法医学研究提供了有用的方法和基础资料。 Abstract:The study is to reveal the diversity and gene structure of 5′ and 3′ end of DYF155S1 locus in Y-chromosome minisatellite among Chinese Uygur population.Fluorescent MVR-PCR（minisatellite variant repeat by PCR）,Amp-FLP(Amplified fragment length polymorphism) and DNA sequencing methods were used repectively to detect 106 unrelated males among Chinese Uygur population.The polymorphisms of DYF155S1 locus could be revealed in three aspects:(1) polymorphic length:the sizes of amplified fragments ranged from 1405 to 2505bp.There are 37 types found among the 106 unrelated males.(2) polymorphism at 5′ end of DYF155S1 locus,68 types found among the 106 unrelated males.(3) polymorphism at 3′ end of DYF155S1 locus,23 types found among the 106 unrelated males.In combination of these three aspects of polymorphism,none of the 106 unrelated males tested had the same allele,and the gene diversity(h) was over 0.9999.Seven and two types of modular structure were founded in the 5′ and 3′ end of DYF155S1 locus,respectively,by DNA sequencing.The alleles at DYF155S2 locus showed yes/no dimorphism and the rate of deletion was 4.7%.The polymorphisms of DYF155S1 locus were fully revealed by using combination of MVR-PCR, Amp-FLP and DNA sequencing methods, and we suggested the nomenclature for alleles of MVR loci.These methods are useful tools and provide basic data for the study of human genetics and forensic medicine.     

Loss of duplicate gene expression in tetraploid Chenopodium

Genetic analyses indicate that single-banded leucine aminopeptidase (LAP) phenotypes in tetraploid Chenopodium reflect homozygosity for null alleles at either locus of a polyduplicated pair. Other duplicated isozyme loci show simplification to the diploid phenotype. Loss of duplicate gene expression in the LAP system has occurred independently in putatively specialized taxa occupying the distributional periphery of a New World tetraploid complex. The geographic/taxonomic pattern of genetic variation suggests that fixation of null alleles is mediated by stochastic genetic phenomena associated with migration. Plants homozygous for null alleles at both LAP loci show no detetable activity in assays involving several exopeptidase substrates, although growth and fertility of double-null plants are not markedly reduced. Our data confirm that loss of duplicate gene expression can occur in isozyme systems of polyploid plant taxa. Thus, lack of electrophoretically detectable duplicate gene expression is not a certain indication of diploidy. However, loss of duplicate gene expression in population systems known to be of allopolyploid origin is a clear indication of phyletic derivation.     

The genetics of the sixth and seventh components of complement in the dog: Polymorphism,linkage, locus duplication,and silent alleles

The complement components C6 and C7 exhibit genetic polymorphism in the domestic dog. In the case of C6, there is a single locus with a null allele and two structural alleles; in the case of C7, there are two linked loci, each with three structural alleles. There is a null allele or locus deletion at one of these loci. In all cases, inheritance is autosomal and codominant. The C7 loci are closely linked to each other and to C6. This complex is not close to the dog major histocompatibility complex (MHC) locus.     

Genetic studies of human apolipoproteins. XI. The effect of the apolipoprotein C-II polymorphism on lipoprotein levels in Nigerian blacks

The human apolipoprotein C-II locus exhibits genetically determined structural polymorphism in United States and African blacks. In the present study, we have investigated the effect of the apoC-II polymorphism on quantitative serum levels of total cholesterol, total high density lipoprotein (HDL) cholesterol, cholesterol in high density lipoprotein subfractions, low density lipoprotein (LDL) cholesterol, and triglycerides (TG) in a sample of 368 unrelated Nigerian blacks. The frequencies of the APOC-II*1 and APOC-II*2 alleles in the samples were 0.947 and 0.053, respectively. In males, the effect of the APOC-II*2 allele was to lower the total serum cholesterol and LDL-cholesterol levels by 13.28 mg/dl and 10.55 mg/dl, respectively, relative to the common allele, APOC-II*1. In females, the effect was to lower total plasma cholesterol by 4.49 mg/dl and LDL-cholesterol by 3.21 mg/dl. The effect of apoC-II on quantitative lipoprotein levels is shown to be independent of variation at the linked apoE locus, but the products of the two loci interact in determining overall quantitative phenotypes.     

Allele frequency distribution of the (TG)n(AG)m microsatellite in the apolipoprotein C-II gene.

The dinucleotide (TG)n interspersed repetitive sequences are the most abundant microsatellites in the human genome. Using the polymerase chain reaction to amplify a (TG)n(AG)m microsatellite in the first intron of the apo C-II gene, we have detected 15 different alleles in 242 unrelated individuals of French ancestry. The heterozygosity index was 0.85 and codominant Mendelian inheritance of the alleles was observed in individuals from 121 nuclear families. We report that polymorphism at this locus is attributable to length variation at both (TG)n and (AG)m motifs, although the (AG)m motif contains only two alleles differing by one repeat unit. A quadrimodal allele frequency distribution was observed at the (TG)n(AG)m locus. Each of the first three modes comprises one frequent allele and one very rare allele adjacent in size. No alleles of intermediate size were found between the three first modes. The fourth mode encompasses nine alleles that span from 27 to 35 repeat units. We suggest that this distribution reflects the molecular mechanisms by which alleles give rise to one another.     

Genetic studies of human apolipoproteins. III. Polymorphism of apolipoprotein C-II

Using a simple and rapid one-dimensional isoelectric focusing technique followed by immunoblotting, we have detected genetic polymorphism of human apolipoprotein C-II (APO C-II) in normal unfractionated plasma samples of individuals of black ancestry. Two common autosomal codominantly expressed alleles, designated APO C-II*1 and APO C-II*2, at the APO C-II structural locus have been observed with frequencies of 0.975 and 0.025 in US blacks and 0.943 and 0.049 in Nigerian blacks. In addition, the gene product of a rare allele designated APO C-II*3 was observed in a single Nigerian black. Apart from a single example of an APO C-II 2-1 phenotype in plasma samples from 187 whites, which was electrophoretically identical to the 2-1 phenotype observed in blacks, it appears that APO C-II*2 is a unique black marker of potential importance in anthropogenetic and atherosclerosis studies.     

CYP21 mutations in Brazilian patients with 21-hydroxylase deficiency

Congenital adrenal hyperplasia caused by 21-hydroxylase deficiency is a common autosomal recessive disorder resulting from mutations in the 21-hydroxylase (CYP21) gene. To develop a strategy to screen for the most commonly occurring CYP21 mutations in Brazil, we performed molecular genotype analysis on 73 children with CAH representing 71 unrelated families. The techniques used for CYP21 molecular genotype analysis were: restriction fragment length polymorphism, single-strand conformational polymorphism, allele-specific oligonucleotide hybridization, allele-specific polymerase chain reaction amplification, and heteroduplex analyses. Mutations were identified on all but eight affected alleles. The intron 2 splicing mutation was the most frequently identified mutation. Screening for the most common mutations detected at least one mutation on 132/142 (93%) alleles. Multiple CYP21 mutations were detected on 16.2% of alleles. The high frequency of multiple mutations on a single allele emphasizes the importance of thorough and accurate molecular genotype analysis of the complex CYP21 locus.     

Analysis of the VNTR locus D1S80 by the PCR followed by high-resolution PAGE.

Allelic data for the D1S80 locus was obtained by using the PCR and subsequent analysis with a high-resolution, horizontal PAGE technique and silver staining. Compared with RFLP analysis of VNTR loci by Southern blotting, the approach described in this paper offers certain advantages: (1) discrete allele resolution, (2) minimal measurement error, (3) correct genotyping of single-band VNTR patterns, (4) a nonisotopic assay, (5) a permanent record of the electrophoretic separation, and (6) reduced assay time. In a sample of 99 unrelated Caucasians, the D1S80 locus demonstrated a heterozygosity of 80.8% with 37 phenotypes and 16 alleles. The distribution of genotypes is in agreement with expected values according to the Hardy-Weinberg equilibrium. Furthermore, the observed number of alleles and the level of heterozygosity, obtained through the protocol described here, were congruent with each other in accordance with the expectation of a mutation-drift equilibrium model for a single, homogeneous, random-mating population. Therefore, the analysis of D1S80 and similar VNTR loci by amplified fragment length polymorphism (AMP-FLP) may prove useful as models for population genetic issues for VNTR loci analyzed by RFLP typing via Southern blotting.     

Population genetics of apolipoproteins A-IV, E, and H, and the angiotensin converting enzyme (ACE): associations with lipids, and apolipoprotein levels in American Samoans

Distributions of alleles at three apolipoprotein loci (APO E, APO H, and APO A-IV) and an insertion/deletion (I/D) polymorphism at the angiotensin converting enzyme (ACE) locus among 274 American Samoans are described here. Genotypes at each locus are examined for associations with quantitative lipid (total cholesterol (total-c), LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), and triglycerides) and apolipoprotein (APO AI, APO AII, APO E, and APO B) levels. Genotype frequencies at all four loci are in Hardy-Weinberg equilibrium. The most common APO A-IV genotype (1-1) was observed in 252 American Samoans (97%). The three most common APO E genotypes were 3-3 (47%), 3-4 (30%), and 2-3 (12%). The most frequent APO H genotype was 2-2 (86%). The most common ACE genotype (I/I) was observed in 75% of sampled individuals, and 23% were I/D heterozygotes. APO E genotypic variation was associated with total-c, HDL-c, LDL-c, and all four quantitative apolipoproteins (AI, AII, E, and B). APO A-IV genotypes were associated significantly with total cholesterol, LDL-c, and APO-B levels. APO H showed little association with any quantitative lipid or apolipoprotein. ACE D/D homozygotes had higher AII levels. ACE showed a consistent association with APO AII levels, with either APO A-IV or APO E as a covariate. The interaction term between ACE and APO E was also significantly associated with total-c and APO E levels, and the ACE genotype showed a significant main effect on APO AI levels in multivariate analyses.     

Genetic studies of human apolipoproteins. IV. Structural heterogeneity of apolipoprotein H (beta 2-glycoprotein I).

Human beta 2-glycoprotein I has recently been identified as a component of several human plasma lipoprotein fractions and therefore termed as apolipoprotein H. Its metabolic function in lipid metabolism is not known with certainty, though it may be involved in very-low-density-lipoprotein metabolism. Previously, inherited quantitative variation in beta 2-glycoprotein I has been suggested in man. In this investigation, we document the evidence of genetically determined structural polymorphism of apolipoprotein H or beta 2-glycoprotein I by using thin-layer polyacrylamide isoelectric focusing gels followed by immunological identification by double antibody staining. The apolipoprotein H structural locus is characterized by the occurrence of three common alleles in U.S. whites and blacks. The frequency distributions of the three alleles designated APO H1, APO H2, and APO H3 are .059, .882, and .059 in whites and .017, .902, and .068 in blacks, respectively. In addition, the gene product of a fourth allele, APO H4, has been observed at polymorphic frequency in black individuals and may represent a black marker variant. Family data confirm the hypothesis of four alleles at a single APO H gene locus with an autosomal codominant pattern of inheritance.     

Polymorphism at the ovine major histocompatibility complex class II loci

Southern hybridization analysis of the ovine major histocompatibility complex (MHC) ( MhcOvar ) class II region, using sheep-specific probes for the DQA1, DQA2, DQB and DRA loci, has revealed extensive polymorphism. DQA1 and DQAP had eight and 16 alleles respectively, DQB had six and DRA had three alleles. Little information was derived from the DRB locus owing to extensive cross-hybridization between the DRB probe and the DQB locus. Differences in allele frequency between breeds were revealed. At the DQA1 locus a null allele (DQA1-N) was observed with a frequency of between 27% and 45%, making this the most common DQA1 allele in all breeds examined. The frequency of DQA1-N homozygotes was between 11% and 18%, raising questions as to the functional significance of the DQA1 gene. Linkage analysis between the DQA1, DQA2, DQB and DRA loci did not reveal any recombination.