摘要:

SummaryThe objectives of this study were to elucidate the genetic basis of human deoxyribonuclease II (DNase II) and to evaluate its usefulness as a genetic and/or diagnostic marker. We have devised a novel, specific and highly sensitive assay method for the urinary and leukocytic enzymes (Yasudaet al.1991). The distribution of the activities of both enzymes displayed clear‐cut bimodality and the Japanese study population could be classified into two distinct types, namely low‐activity (DNASE2 L) and high‐activity (DNASE2 H), which indicates the existence of a genetic polymorphism in the activity levels of urinary and leukocytic DNase Us. Close correlations between the leukocytic and urinary enzyme activity levels from the same individuals were observed and the types in the leukocyte samples agreed with the types found in the corresponding urine samples. In a population study of 528 unrelated Japanese individuals, the gene frequencies of the low activity (DNASE2*L) and the high activity (DNASE2*H) alleles were calculated to be 0·632 and 0·368, respectively. The sex and age of individuals did not affect the distribution of DNase II activity levels. The family study results were compatible with the model that the low activity type is due to an autosomal recessive gene, which indicates that DNASE2 L represents homozygosity forDNASE2*Land DNASE2 H corresponds to homozygosity forDNASE2*Hand heterozygosity forDNASE2*LandD

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01125.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryThe genetic relationship amongst apolipoprotein B (apo B) gene polymorphisms (signal peptide insertion/deletion (Leu‐Ala‐Leu‐16/‐14),XbaI (Thr2488),EcoRI (Glu4154→ Lys), Asn4311→ Ser, 3′ ‐VNTR) has been investigated in samples of South Asian (Indian) and Swedish individuals. The frequency distribution of alleles at all these sites was found to be significantly different between the South Asian and the Swedish samples (deletion allele: 0·20v.0·31, X + (presence ofXbaI cutting site): 0·29v.0·55, R‐ (absence ofEcoRI cutting site): 0·11v.0·19, Ser4311: 0·45v.0·19). The distribution of allele frequencies at the VNTR site was bimodal in both populations. However, in South Asians, the most common allele was a 35 repeat unit allele, whilst in the Swedish sample, and in all other reports from Caucasian samples the 37 repeat unit allele was the most frequent (South Asianv.Swedish: 35 allele: 0·36v.0·19, 37 allele: 0·25v.0·48). Furthermore, four new alleles at the apo B gene 3′ ‐VNTR site (15, 17, 32, 38 repeat unit alleles) were observed in South Asians, of which two (15 and 17 repeat unit alleles) were well outside the bimodal distribution. In both samples, strong linkage disequilibrium and allelic association were detected between alleles at the 3′ ‐VNTR and each of the other sites, and also between theins/delandXbaI sites and between theXbaI and Asn4311→ Ser sites. The same five common haplotypes as defined byins/del, XbaI,EcoRI and Asn4311→ Ser were found to be present in both samples comprising 97 and 99 % of the haplotypes observed in the South Asian and Swedish samples respectively. Detailed analysis revealed the predominant occurrence of certain 3′ ‐VNTR alleles on specific haplotypes and demonstrates the usefulness of the VNTR site for haplotyping and representative association studies. A model for the evolutionary relationship of the major haplotypes including the 3′ ‐VNTR site is presented. These findings support a mechanism of replication slippage as a major factor for the generation of new alleles at the apo B

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01126.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryRed blood cell S‐adenosylhomocysteine hydrolase (AHCY) from individuals of 1, 2‐1 and 3‐1 phenotypes was partially purified andKmandVmaxdetermined in the absence and in the presence of the following inhibitors: 3‐deaza‐adenosine (DZA), 3‐deaza‐aristeromycin (DZAry), 2–chloro adenosine (2‐Cl‐ado) and purine riboside (or nebularine). The three phenotypes 1, 2‐1, 3‐1 showed similarKm(32·58, 39·22 and 34·84 μmrespectively), but the ratioKm/Vmaxwas statistically different. DZA and DZAry appeared to be strong competitive inhibitors. The AHCY 1 phenotype was more resistant to their action, while the 3‐1 variant was more sensitive. 2‐Cl‐ado and purine riboside were weaker inhibitors; the type of inhibition varied among the three phenotypes, but, again, the AHCY 1 phenotype was

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01127.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryRestriction fragment length polymorphisms (RFLP) analysis using the Southern blot technique can be used to recognize copy number variation of variable number of tandem repeats (VNTR) of conserved core sequences at several regions of the human genome. This new class of polymorphisms reveals a high degree of genetic variation, useful for individual identification purposes. Criticisms against forensic applications of such DNA typing data include the limitation of employing Hardy Weinberg expectation of genotype frequencies, since several surveys indicate apparent deficiency of heterozygosity (or excess homozygosity) in comparison with Hardy‐Weinberg expectations. This research postulates an alternative explanation of deficiency of apparent heterozygosity which is caused by the inability to detect extremely small‐sized alleles (called ‘non‐detectable’ alleles) due to the sensitivity of Southern gel electrophoresis. We show that the presence of ‘non‐detectable’ alleles can produce pseudo‐homozygosity and their frequencies can be predicted from the observed proportional heterozygote deficiency. Furthermore, in the covert presence of such ‘non‐detectable’ alleles, we show that the gene‐count method provides over‐estimates of allele frequencies in the sample population, and hence the Hardy Weinberg predictions of genotype frequencies avoid wrongful bias against suspects in forensic applications of DNA typing data. Applications of this theory to population data on six VNTR loci in US Caucasians and US Blacks suggest that the presence of ‘non‐detectable’ alleles could be the major cause of apparent heterozygote deficiency, and the current approaches of predicting the population frequency of specific DNA phenotypes are practically free of the possible wrongful bias in courtroo

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01128.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryThis theoretical approach to multiple markers considers the problem of a trait locus flanked by an arbitrary number of linked, ordered markers. Using the criterion of the Expected LOD score (ELOD) for mating, an algorithm is developed to specify the subset of markers required to provide the full linkage information available from a given parental genotype.

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01129.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryA type of Venn diagram is described which enables the observed frequencies in a 2 × 2 × 2 contingency table to be compared with their expectations on the hypothesis of no association

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01130.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01131.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01132.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0003-4800    

DOI:10.1111/j.1469-1809.1992.tb01133.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY