Complement component C3: molecular basis of the C3*S025 variant and evidence for molecular heterogeneity of other variants.

Complement component 3 (C3) is the central molecule of the complement system. It displays a number of polymorphic variants with, as yet, unclear functional consequences. We have investigated a number of rare C3 variants by PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) analysis and could identify the molecular basis of a C3*S025 variant. The decreased electrophoretic mobility of this protein is caused by the exchange of a neutral serine residue to an arginine residue (positively charged). This exchange is unlikely to have functional consequences as it maps to the C-terminus of the alpha-chain. C3 variants appear to have originated from various independent mutat…

Application of DNA techniques for identification using human dental pulp as a source of DNA

Dental pulp tissue could be obtained in most cases from materials obtained under experimental conditions and from forensic casework (air accidents, burned and putrefied bodies). Teeth extracted during dental treatment (n = 30) were stored for 6 weeks and 4 years at room temperature. In addition teeth (n = 10) extracted from jaw fragments that had been stored for 15 years at room temperature, and teeth extracted post mortem from actual identification cases (n = 8) were investigated. Following extraction from dental pulp tissue the DNA concentration was measured by fluorometry. The amount of DNA obtained from the dental pulp tissue of a single tooth varied from 6 micrograms to 50 micrograms D…

GENETIC POLYMORPHISM OF THE FOURTH COMPONENT OF HUMAN COMPLEMENT: POPULATION STUDY AND PROPOSAL FOR A REVISED NOMENCLATURE BASED ON GENOMIC PCR TYPING OF RODGERS AND CHIDO DETERMINANTS

SUMMARY The fourth component of human complement (C4) is coded for by two homologous genes, C4A and C4B, located in the class III region of the major histocompatibility complex (MHC). Genetic typing of C4A and B alleles is routinely carried out by high-voltage agarose gel electrophoresis. The electrophoretic C4 polymorphism can be further subdivided by the Rodgers (Rg) and Chido (Ch) blood groups, which are antigenic determinants of the C4A and B alpha-chains, respectively. We have used a recently described direct PCR typing method using sequence-specific primers (PCR-SSP) in combination with electrophoretic C4 typing as well as genomic RFLP analysis to determine the frequency of C4 allotyp…

C3 reference typing report and nomenclature revision.

As the result of reference typing, two 'new' variants could be provisionally accepted (C3F045 and C3F015). The list of variants of the C3 polymorphism includes now 2 common and 29 rare variants.

Forensic mtDNA hair analysis excludes a dog from having caused a traffic accident

A dog was suspected of having caused a traffic accident. Three hair fragments were recovered from the damaged car and subjected to DNA sequence analysis of the canine mitochondrial D-loop control region. The results were compared to saliva and hair samples from the alleged dog, as well as to control hair samples from four unrelated dogs of different breeds. Two sequence types exhibiting five nucleotide differences in a 377 bp fragment were identified among the four controls. Whereas the evidence hair fragment was identical to the type 1 control sequence, the alleged dog shared the type 2 control sequence except for one position. Thus the dog could be excluded as the origin of the hair fragm…

Application of DNA Polymorphisms in Paternity Testing in Germany: Solution of an Incest Case Using Bacteriophage M13 Hybridization with Hypervariable Minisatellite DNA

More than 25 blood, serum, and enzyme polymorphisms have been introduced into paternity testing in Germany in recent years (Rittner, 1975). If a “no” decision is defined by exclusion, and a “yes” decision requires a probability of 99.73 % or more, more than 90 % of court cases can be solved in this respect. A few cases not being clarified by a standard expertise include: 1) Cases with more than one alleged man if the men and/or the mother and the men are related. 2) Some cases where the putative father is deceased, and neither the parents nor the legitimate offspring are available for the study. 3) Cases where possible exclusion in a given polymorphic system interferes with an overall evide…

Reliability of Restriction Enzyme Digestions of Genomic DNA for the Generation of DNA Fingerprints

Since minisatellite DNA probes are used for the detection of hypervariable loci in eucaryotic genomes [1] the application of so called DNA fingerprints and DNA technology itself in paternity testing and forensic casework is critically discussed ([3]; Brinkmann et al., this volume). A particular problem is the possibility of obtaining partially digested genomic DNA in casework after treatment with restriction enzymes leading to inconclusive or even false results. This is even more important when multilocus DNA probes are used, since the total number of fragments in a given person is not known in advance. But also with single locus probes, where only two allelic fragments are usually detected…

Cholinesterase variants: rapid characterisation by PCR/SSCP and evidence for molecular homogeneity.

We have applied the technique of PCR-SSCP (polymerase chain reaction-single stranded conformation polymorphism) to characterise the molecular basis of cholinesterase deficiency and variants in a Jordanian family. PCR-SSCP proved to be a quick and sensitive method of screening cholinesterase variants in a clinical setting. An AG insertion at position 351 was found to cause a silent allele, for which the parents were heterozygous and three children homozygous. In addition, the father and two sons were heterozygous for an A to G transition at position 209, known to cause the dibucaine resistant variant. No linkage to the K variant was found, which has been reported previously in white populati…

Bgl II restriction fragment length polymorphism of human complement C4A gene coincides with BF*F allele of factor B.

Minisatellite DNA Probe MZ 1.3: Application in Paternity Testing and Estimate of the Number of Genetic Loci

The use of hypervariable DNA minisatellite probes recognizing repetitive genomic DNA sequences has become a valuable and powerful tool in paternity testing as well as in forensic stain analysis (Jeffreys et al. 1985, 1987; Werrett et al. 1988). It has been shown that bacteriophage Ml3 DNA can also be used to obtain hypervariable DNA restriction fragment patterns in humans and other species (Vassart et al. 1987). To obtain more informative and specific fragment patterns for the DNA ‘fingerprint’ analysis in man, we have used Ml3 DNA as a probe to screen a human genomic library. Thus, we have isolated the minisatellite DNA probe MZ 1.3 (Schacker et al., in press). MZ 1.3 is a 1.9 kb fragment …

Quantitative and qualitative analysis of DNA extracted from postmortem muscle tissues

DNA extracted from 33 postmortem muscle specimens was analyzed using MZ 1.3, a hypervariable minisatellite probe, as well as locus-specific minisatellite probes (g3, MS1 and MS43). After storage at -25 degrees C for 10 months, DNA from all the samples was partially (approximately 21% of total DNA) degraded even when autopsy was performed 1 day postmortem. However, more than 90% of DNA samples up to at least 3 days postmortem were suitable to obtain good restriction fragment length polymorphism (RFLP) patterns. When small strips of specimen were stored for 8 days at room temperature in moist chambers, approximately 42% of total DNA was degraded. Only 30% of these DNA samples still showed goo…

Mechanism of fatal air embolism after gastrointestinal endoscopy.

Although venous air embolism is a known complication in medical practice in general, only a single case of upper gastrointestinal endoscopy complicated by venous air embolism with consecutive acute cardiovascular failure has so far been described in literature. Here we show that gastroscopy may be accompanied by massive, i.e. fatal venous air embolism. If a vessel in the gastrointestinal tract is exposed but does not collapse (in the case of a gastric ulcer, for example) air insufflated under pressure by the gastroscope may lead to a fatal air embolism. Our tests using a commercial gastroscope revealed that an overpressure of up to 43 kPa (kiloPascals) is reached without the rinsing functio…

C8 Reference Typing Report and Nomenclature Recommendation

Using two different typing techniques (i.e. polyacrylamide gel isoelectric focusing (PAGIF) with Western blot and SDS-polyacrylamide gel electrophoresis of precipitated C8 under nonreducing conditions with Western blot), the following observations were made during the reference typing for C81 (C8A). The Japanese variant A1J is probably identical with A1Cauc, whereas B1J is definitely different from B1Cauc and could therefore provisionally be named HB3'. Variant 'A2' from Japan is focused in an intermediate position, but different from M1 and could be named 'M2'. Both variants possess normal A subunits. B2 from Japan is clearly different from B1Cauc and should retain its designation. In PAGI…

The endogenous retroviral insertion in the human complement C4 gene modulates the expression of homologous genes by antisense inhibition

Intron 9 contains the complete endogenous retrovirus HERV-K(C4) as a 6.4-kb insertion in 60% of human C4 genes. The retroviral insertion is in reverse orientation to the C4 coding sequence. Therefore, expression of C4 could lead to the transcription of an antisense RNA, which might protect against exogenous retroviral infections. To test this hypothesis, open reading frames from the HERV sequence were subcloned in sense orientiation into a vector allowing expression of a beta-galactosidase fusion protein. Mouse L cells which had been stably transfected with either the human C4A or C4B gene both carrying the HERV insertion (LC4 cells), and L(Tk-) cells without the C4 gene were transiently tr…

Lack of linkage between gene(s) controlling the synthesis of the seventh component of complement and the HLA region on chromosome No. 6 in man.

The family of an individual was studied who lacks the seventh component of complement in his serum (C7 homozygous deficiency). Both parents are C7 heterozygousdeficient. In this investigation, the following parameters were determined: complement components in functional and immunochemical tests; HLA-A,B antigens, HLA-D (MLC) determinants; the Bf system; glyoxalase I and B cell antigens. No evidence for linkage between the immunogenetic linkage group on chromosome 6 and gene(s) controlling the synthesis of the seventh component of complement was obtained. This is in accordance with the assumption that only genes controlling components of the initiating rather than the membrane attack unit of…

HLA DQα Typing of Human Fingernails

In contrast to the extensive knowledge about protein biochemistry of keratinization, little is known about the fate of nuleic acids during these processes (1). It has been suggested that both DNA and RNA completely degenerate in the initial phase of keratinization. However, from electron microscopical studies it is known that nuclear remnants are present (1,3). From these findings and own observations one might expect that nucleic acids should still be available.

The human complement C9 gene: structural analysis of the 5′ gene region and genetic polymorphism studies

Summary C9 is the last of the human complement components creating the membrane attack complex. The single chain serum protein is encoded by a gene located on chromosome 5p13 that is composed of 11 exons. With the aid of inverse PCR, the hitherto unknown regions flanking exon 1 and the 3′ part of exon 11 (3′UTR) have been sequenced. A computer-based analysis of the 300-bp region located just upstream of the AUG start codon showed homologies to known DNA modules which affect the transcriptional regulation of certain genes. The most striking of these is a sequence that may substitute the missing TATA box in initiating C9 transcription. In the 3′UTR, three successive polyadenylation signals we…

Differential regulation of interleukin-10 production by genetic and environmental factors – a twin study

Interleukin-10 (IL-10) has a critical role in the regulation of immune responses. The relative contribution of genetic and environmental factors to IL-10 production is under debate. We performed a twin study in 246 monozygotic and dizygotic twins to assess the heritability of IL-10 production after LPS stimulation in whole blood. In addition, the influence of promoter single nucleotide polymorphisms (-1082, -819 and -592) on transcriptional activity and their binding to nuclear factors was studied in luciferase reporter gene and electrophoretic mobility shift assays. IL-10 production showed a genetic determination with a heritability of 0.5. Decreasing body mass index (BMI), smoking and fem…

Zur R�ntgenidentifizierung unbekannter Leichen bei fortgeschrittenen postmortalen Ver�nderungen

Die postmortalen Veranderungen an einer Wasserleiche und an einer Brandleiche waren so weit fortgeschritten, das die ublichen Identifizierungsmethoden versagen musten. Vergleichende rontgenologische Untersuchungen ermoglichten jedoch den sicheren Nachweis der Identitat. Der Erfolg beruhte auf der individuellen Variabilitat des Skelettsystems und seiner hohen Widerstandsfahigkeit gegenuber intravitalen und postmortalen Einflussen. Neben der hohen Aussagekraft sind einfache, schnelle Handhabung sowie Dokumentation — ohne Beeintrachtigung der Obduktion — weitere Vorteile der Rontgenidentifizierung. Die vorgestellten Falle zeigen zudem, das auch zehn Jahre alte intravitale Vergleichsbilder zur …

Genotyping of 9 STR systems in combination with 11 diallelic polymorphisms on the Y-chromosome by fragment analysis and minisequencing

1. IntroductionThe study of Y chromosomal haplotypes and their relationship to human evolution andvariation is increasing rapidly in the fields of anthropology and forensic genetics.Although autosomal STRs are commonly used and very informative for paternity testingand forensic identification, the use of the nonrecombining portion of the Y chromosome isimportant and provides additional data in cases when the offspring is a male or for mixedmale/female crime stains. For this purpose, in the past 2 years, more and more attentionhas been paid to the examination of diallelic polymorphisms (SNPs) on the Y chromosome[1].Here, we describe an approach for the typing of 10 Y-chromosomal diallelic po…

Genetic basis of human complement C4A deficiency. Detection of a point mutation leading to nonexpression.

Abstract The fourth component of the human complement system (C4) is coded for by two genes, C4A and C4B, located within the MHC. Null alleles of C4 (C4Q0) are defined by the absence of C4 protein in plasma. These null alleles are due either to large gene deletions or to nonexpression of the respective genes. In a previous study, evidence was obtained for nonexpressed defective genes at the C4A locus, and for gene conversion at the C4B locus. To further characterize the molecular basis of these non-expressed C4A genes, we selected nine pairs of PCR primers from flanking genomic intron sequences to amplify all 41 exons from individuals with a defective C4A gene. The amplified products were s…

Null alleles of human complement C4. Evidence for pseudogenes at the C4A locus and for gene conversion at the C4B locus

The two genes for the C4A and C4B isotypes of the fourth component of human complement are located in the MHC class III region. Previous studies have demonstrated the unusual expression of C4 genes in the form of aberrant or duplicated haplotypes. Null alleles of C4A or C4B (AQ0 or BQ0) have been defined by the absence of gene products and occur at frequencies of 0.1-0.3. However, only some C4 null alleles are due to gene deletions, the remainder were thought to be nonexpressed genes. We have analyzed the C4 gene structure of 26 individuals lacking either C4A or C4B protein. The DNA of individuals with apparently nonexpressed C4 genes was tested for the presence of C4A- and C4B-specific seq…

Fatal cerebellar haemorrhage due to phenprocoumon poisoning.

A 32-year-old patient died of a cerebellar haemorrhage and the blood coagulation analysis before death suggested defective synthesis of vitamin K-dependent clotting factors due to vitamin K deficiency. The post-mortem toxicological examination of different tissues revealed phenprocoumon poisoning as the cause of death. The differential diagnosis of vitamin K deficiency and the toxicology of hydroxycoumarins are discussed.

Possible association of sudden infant death with partial complement C4 deficiency revealed by post-mortem DNA typing of HLA class II and III genes

Based on evidence of an increased rate of respiratory infections in sudden infant death (SID) infants as well as the observation of familial occurrence, we analysed in a retrospective study class II and class II genes of the major histocompatibility complex in 40 cases of SID by Southern blot analysis of DNA obtained post mortem from tissue samples. In 24 cases, the parents were interviewed and confirmatory human lymphocyte antigen (HLA) and DNA typing was carried out. Using HLA-DR beta and -DQ beta probes, no evidence of an abnormal HLA-DR frequency distribution in SID infants was detected (P = 0.97). Using DNA probes for the tandemly arranged complement C4 and steroid 21-hydroxylase genes…

No Association between Mannose-Binding Lectin Alleles and Susceptibility to Chronic Hepatitis B Virus Infection in German Patients

Variants of the mannose-binding lectin (MBL) have been shown to be associated with low serum concentrations of the protein and to predispose to bacterial, fungal and viral infections. A recent small study on 33 Caucasian patients had suggested that a mutation at codon 52 of the MBL gene is associated with chronic hepatitis B virus (HBV) infection. Exon 1 of the MBL gene was amplified by PCR in 61 patients with chronic HBV infection, 28 patients with acute infection and in 60 controls. MBL variants were detected by subsequent restriction enzyme digestion and agarose gel electrophoresis. The occurrence of the codon 52 mutation in patients with chronic HBV infection did not differ significantl…

Quantification of fluorescent STR genotyping results for chimerism control after bone marrow transplantation

1. IntroductionEngraftment of donor stem cells after allogeneic bone marrow transplantation can begenetically monitored by PCR typing of DNA polymorphisms [1]. Successful engraftmentwith complete chimerism and presence of the donor’s genotype in the bone marrow has tobe demonstrated, and the presence of the patient’s alleles has to be excluded. Detection ofthe patient’s alleles provides evidence for an incomplete chimerism or for a relapse ofmalignant disease. STRs have been used successfully for this type of genetic monitoring[2]. For the present study, we have developed an approach to quantify the ratio of donorchimerism using mock mixture experiments. The usefulness of our approach is de…

Report of a european collaborative exercise comparing DNA typing results using a single locus VNTR probe

A collaborative exercise was carried out in 1989 among 12 European forensic laboratories using the single locus VNTR probe pYNH24, the restriction enzyme HinfI, the same set of human genomic DNA samples, and a standardized DNA size marker. The objectives of the exercise were: (1) to study the degree of variation within and between laboratories, (2) to obtain information on requirements for technical standardization allowing the exchange of typing results and (3) to compare different approaches for the identification of allelic DNA fragments of unknown size. Each laboratory carried out up to 10 independent typing experiments using the same DNA samples. The results were analysed independently…

Use of the software ‘Poser4’ in reconstruction of accident and crime scenes

The reconstruction of accident and crime scenes demands the full attention of the forensic working physician. Description by words is often difficult and liable to be misunderstood. Reconstruction in the original places of events are expensive and in some cases impossible. Computer graphics and animations give the possibility to construct the original course of events. Poser4 is a software package to perform these reconstructions in an easy and vivid way. We investigated the possibilities of reconstructing an accident with this software.

Isolation of the DNA minisatellite probe MZ 1.3 and its application to DNA ‘fingerprinting’ analysis

Abstract A minisatellite probe, MZ 1.3, detecting hypervariable fragment patterns was isolated from a human genomic library. A repetitive sequence of 27 bp length was identified which is contained in the probe approx. 40 times. The MZ 1.3 repeat shows variable homology of 53–73% to the repetitive sequence of the protein III gene of the bacteriophage M13 genome. Polymorphic restriction fragment patterns were found with MZ 1.3 using the enzymes Hinf I, BstN I, Hae III, Mbo I, PstI PvuII , and Rsa I. An average of 18 polymorphic fragments was observed using Hinf I as enzyme. The band sharing frequency after Hinf I digestion among unrelated individuals was determined to be 23.8 ± 7.2%. An examp…

No primary association between LMP2 polymorphisms and extraspinal manifestations in spondyloarthropathies

OBJECTIVE—To investigate the potential role of the HLA-linked LMP2 (low molecular weight protein) gene polymorphisms in conjunction with DR4 and DR7 on extraspinal disease manifestations in HLA-B27 positive patients with spondyloarthropathy.
METHODS—172 patients with spondyloarthropathy, 46 healthy, HLA-B27 positive blood donors, and 99 unrelated controls were typed for HLA-class I and II antigens. LMP2 alleles were determined by polymerase chain reaction and subsequent restriction enzyme digestion.
RESULTS—There were statistically non-significant increases of DR4 and DR7 in spondyloarthropathy subjects. However these differences did not relate to specific extraspinal manifestations. There …

Development of a quadruplex PCR system for the genetic analysis of X-chromosomal STR loci

Short tandem repeat systems on the X chromosome are the natural counterpart to the well-established Y-chromosomal STR loci. The X-linked systems are inherited as a single haplotype only in males, whereas in females, the X chromosomes recombine and exhibit the same characteristics as the autosomes. Nevertheless, X-linked systems may provide a useful tool in paternity cases with female offspring, in particular when the alleged father is not available for testing, or in forensic identification cases based on the comparison with firstor second-degree relatives. Only a small number of STR loci have been described on the X chromosome, and a number of these are not highly informative. Therefore, w…

C4 Alpha-Chain Reference Typing Report

Previously it was shown that C4A and C4B alpha-chains after separation on SDS-PAGE can provide valuable information on presence and absence, as well as the number of C4A and C4B genes expressed in an individual. All samples submitted for C4 reference typing were also subjected to C4 alpha-chain separation; the results were included in the Final C4 Reference Typing List [Complement Inflamm 1990;7:193-212]. In addition, in selected cases with assumed 'reversed antigenicity', Western blots of C4 alpha-chains with monoclonal anti-C4A and B antibodies were obtained. As a result, subtypic differences of C4B allotypes were detected by the comparison of monoclonal antibodies 1217 and 1228.

Sequence analysis of the DRB1 promoter reveals limited polymorphism with no influence on gene expression.

HLA-class II promoters contain a set of conserved regulatory regions necessary for constitutive and induced gene expression. For the HLA-DQB as well as for the DRB1 promoter sequence, polymorphisms with influence on gene expression have been reported. In contrast to these data we could show that there is very limited allele-specific polymorphism among the HLA-DRB1 promoter alleles. In a long range PCR we amplified a DNA sequence containing the promoter and the second exon of the DRB1 gene in one fragment. Nested PCR products of this PCR fragment for the promoter and for the second exon were analysed by DNA sequencing to allow the linkage of a promoter to its DR allele. Most investigated DRB…

DNA Fingerprinting as a Tool of Paternity Testing in Germany

Soon after the discovery of the ABO blood groups by Landsteiner their forensic application was suggested by Max Richter at the 74. Versammlung Deutscher Naturforscher und Arzte at Karlsbad (Karlovy Vary) in 1902 [1], Landsteiner’s Nobel lecture “Uber individuelle Unterschiede des menschlichen Blutes” in 1930 [2] provided a landmark on the path towards the discovery of so-called hypervariable minisatellite regions of human DNA by Alec Jeffreys in 1985 [3]. Since the individual patterns of any human being seemed to be unique it is well understood that this achievement was immediately welcomed with great enthusiasm by the scientific community and the public opinion. Soon thereafter, however, s…

Sex Determination by Genomic Dot Blot Hybridization and HLA DQα Typing by PCR from Fixed Tissues

Recent advances in molecular biology methods have significantly increased the ability to detect genetic variation at the genomic level for forensic purposes. However, the quality requirements for blood, fresh or frozen tissue as a source of DNA are a practical limitation for typing the victim in order to conduct investigations on unsolved cases. Since paraffin embedded specimens are easily obtainable the ability to study this material would be of great value in current forensic practice.

Genetic analysis of IDDM: The GAW5 multiplex family dataset

In a collaborative effort by 12 centers from Europe and North America, data were assembled from 94 multiplex families with insulin-dependent diabetes mellitus (IDDM) for analysis of genetic and other factors of possible etiological importance. The dataset contains information on the following genetic markers: HLA-DR beta and -DQ beta restriction fragment length polymorphisms (RFLPs), three RFLPs detected with two probes that map 5' to the insulin gene, the serologically defined HLA loci, and the immunoglobulin allotypes. Data also were included for auto-antibodies to insulin and pancreatic islet cells as possible indicators of pathogenesis and for antibodies to certain viruses that have bee…