Polymorphism, Genetic
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
Polymorphism, Single Nucleotide
Genetic Predisposition to Disease
Gene Frequency
The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.
Alleles
Haplotypes
Case-Control Studies
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
Genotype
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Polymerase Chain Reaction
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Polymorphism, Single-Stranded Conformational
Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.
Genetic Association Studies
The analysis of a sequence such as a region of a chromosome, a haplotype, a gene, or an allele for its involvement in controlling the phenotype of a specific trait, metabolic pathway, or disease.
Linkage Disequilibrium
Asian Continental Ancestry Group
Sequence Analysis, DNA
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Base Sequence
Genetic Markers
Homozygote
An individual in which both alleles at a given locus are identical.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Risk Factors
Phenotype
Methylenetetrahydrofolate Reductase (NADPH2)
European Continental Ancestry Group
Individuals whose ancestral origins are in the continent of Europe.
Amplified Fragment Length Polymorphism Analysis
The detection of RESTRICTION FRAGMENT LENGTH POLYMORPHISMS by selective PCR amplification of restriction fragments derived from genomic DNA followed by electrophoretic analysis of the amplified restriction fragments.
Heterozygote
An individual having different alleles at one or more loci regarding a specific character.
Promoter Regions, Genetic
Exons
The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.
Odds Ratio
The ratio of two odds. The exposure-odds ratio for case control data is the ratio of the odds in favor of exposure among cases to the odds in favor of exposure among noncases. The disease-odds ratio for a cohort or cross section is the ratio of the odds in favor of disease among the exposed to the odds in favor of disease among the unexposed. The prevalence-odds ratio refers to an odds ratio derived cross-sectionally from studies of prevalent cases.
DNA Primers
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Chromosome Mapping
Any method used for determining the location of and relative distances between genes on a chromosome.
Microsatellite Repeats
A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).
Genome-Wide Association Study
An analysis comparing the allele frequencies of all available (or a whole GENOME representative set of) polymorphic markers in unrelated patients with a specific symptom or disease condition, and those of healthy controls to identify markers associated with a specific disease or condition.
Mutation
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Genetic Linkage
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
Peptidyl-Dipeptidase A
A peptidyl-dipeptidase that catalyzes the release of a C-terminal dipeptide, -Xaa-*-Xbb-Xcc, when neither Xaa nor Xbb is Pro. It is a Cl(-)-dependent, zinc glycoprotein that is generally membrane-bound and active at neutral pH. It may also have endopeptidase activity on some substrates. (From Enzyme Nomenclature, 1992) EC 3.4.15.1.
Genetics, Population
The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.
Glutathione Transferase
Catechol O-Methyltransferase
Amino Acid Substitution
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
Introns
DNA
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Pharmacogenetics
Minisatellite Repeats
Tandem arrays of moderately repetitive, short (10-60 bases) DNA sequences which are found dispersed throughout the GENOME, at the ends of chromosomes (TELOMERES), and clustered near telomeres. Their degree of repetition is two to several hundred at each locus. Loci number in the thousands but each locus shows a distinctive repeat unit.
Glutathione S-Transferase pi
A glutathione transferase that catalyzes the conjugation of electrophilic substrates to GLUTATHIONE. This enzyme has been shown to provide cellular protection against redox-mediated damage by FREE RADICALS.
Models, Genetic
Cohort Studies
Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
Codon
A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).
Deoxyribonucleases, Type II Site-Specific
Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. The corresponding modification methylases are separate enzymes. The systems recognize specific short DNA sequences and cleave either within, or at a short specific distance from, the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. EC 3.1.21.4.
INDEL Mutation
A mutation named with the blend of insertion and deletion. It refers to a length difference between two ALLELES where it is unknowable if the difference was originally caused by a SEQUENCE INSERTION or by a SEQUENCE DELETION. If the number of nucleotides in the insertion/deletion is not divisible by three, and it occurs in a protein coding region, it is also a FRAMESHIFT MUTATION.
Risk
Serotonin Plasma Membrane Transport Proteins
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of serotonergic neurons. They are different than SEROTONIN RECEPTORS, which signal cellular responses to SEROTONIN. They remove SEROTONIN from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. Regulates signal amplitude and duration at serotonergic synapses and is the site of action of the SEROTONIN UPTAKE INHIBITORS.
Selection, Genetic
Xeroderma Pigmentosum Group D Protein
A DNA helicase that is a component of TRANSCRIPTION FACTOR TFIIH. It plays an essential role in NUCLEOTIDE EXCISION REPAIR, and mutations in this protein are associated with XERODERMA PIGMENTOSUM.
Pedigree
Genotyping Techniques
Methods used to determine individuals' specific ALLELES or SNPS (single nucleotide polymorphisms).
Aryl Hydrocarbon Hydroxylases
A large group of cytochrome P-450 (heme-thiolate) monooxygenases that complex with NAD(P)H-FLAVIN OXIDOREDUCTASE in numerous mixed-function oxidations of aromatic compounds. They catalyze hydroxylation of a broad spectrum of substrates and are important in the metabolism of steroids, drugs, and toxins such as PHENOBARBITAL, carcinogens, and insecticides.
Genetic Loci
Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.
Publication Bias
The influence of study results on the chances of publication and the tendency of investigators, reviewers, and editors to submit or accept manuscripts for publication based on the direction or strength of the study findings. Publication bias has an impact on the interpretation of clinical trials and meta-analyses. Bias can be minimized by insistence by editors on high-quality research, thorough literature reviews, acknowledgement of conflicts of interest, modification of peer review practices, etc.
Korea
Genetic Testing
Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.
Species Specificity
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
DNA Fingerprinting
A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.
Receptors, Calcitriol
Proteins, usually found in the cytoplasm, that specifically bind calcitriol, migrate to the nucleus, and regulate transcription of specific segments of DNA with the participation of D receptor interacting proteins (called DRIP). Vitamin D is converted in the liver and kidney to calcitriol and ultimately acts through these receptors.
Aryldialkylphosphatase
An enzyme which catalyzes the hydrolysis of an aryl-dialkyl phosphate to form dialkyl phosphate and an aryl alcohol. It can hydrolyze a broad spectrum of organophosphate substrates and a number of aromatic carboxylic acid esters. It may also mediate an enzymatic protection of LOW DENSITY LIPOPROTEINS against oxidative modification and the consequent series of events leading to ATHEROMA formation. The enzyme was previously regarded to be identical with Arylesterase (EC 3.1.1.2).
Evolution, Molecular
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
Arylamine N-Acetyltransferase
An enzyme that catalyzes the transfer of acetyl groups from ACETYL-COA to arylamines. It can also catalyze acetyl transfer between arylamines without COENZYME A and has a wide specificity for aromatic amines, including SEROTONIN. However, arylamine N-acetyltransferase should not be confused with the enzyme ARYLALKYLAMINE N-ACETYLTRANSFERASE which is also referred to as SEROTONIN ACETYLTRANSFERASE.
Genome, Human
Point Mutation
Mutation, Missense
Cytochrome P-450 CYP1A1
A liver microsomal cytochrome P-450 monooxygenase capable of biotransforming xenobiotics such as polycyclic hydrocarbons and halogenated aromatic hydrocarbons into carcinogenic or mutagenic compounds. They have been found in mammals and fish. This enzyme, encoded by CYP1A1 gene, can be measured by using ethoxyresorufin as a substrate for the ethoxyresorufin O-deethylase activity.
Ethnic Groups
Logistic Models
Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.
Dinucleotide Repeats
The most common of the microsatellite tandem repeats (MICROSATELLITE REPEATS) dispersed in the euchromatic arms of chromosomes. They consist of two nucleotides repeated in tandem; guanine and thymine, (GT)n, is the most frequently seen.
Tandem Repeat Sequences
Copies of DNA sequences which lie adjacent to each other in the same orientation (direct tandem repeats) or in the opposite direction to each other (INVERTED TANDEM REPEATS).
Amino Acid Sequence
Chi-Square Distribution
A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.
Age of Onset
5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase
An enzyme that catalyzes the formation of methionine by transfer of a methyl group from 5-methyltetrahydrofolate to homocysteine. It requires a cobamide coenzyme. The enzyme can act on mono- or triglutamate derivatives. EC 2.1.1.13.
Diabetes Mellitus, Type 2
A subclass of DIABETES MELLITUS that is not INSULIN-responsive or dependent (NIDDM). It is characterized initially by INSULIN RESISTANCE and HYPERINSULINEMIA; and eventually by GLUCOSE INTOLERANCE; HYPERGLYCEMIA; and overt diabetes. Type II diabetes mellitus is no longer considered a disease exclusively found in adults. Patients seldom develop KETOSIS but often exhibit OBESITY.
Valine
Cytochrome P-450 CYP2E1
An ethanol-inducible cytochrome P450 enzyme that metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. Substrates include ETHANOL; INHALATION ANESTHETICS; BENZENE; ACETAMINOPHEN and other low molecular weight compounds. CYP2E1 has been used as an enzyme marker in the study of alcohol abuse.
Colorectal Neoplasms
Tumors or cancer of the COLON or the RECTUM or both. Risk factors for colorectal cancer include chronic ULCERATIVE COLITIS; FAMILIAL POLYPOSIS COLI; exposure to ASBESTOS; and irradiation of the CERVIX UTERI.
3' Untranslated Regions
Epistasis, Genetic
A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.
Bacterial Typing Techniques
Glucuronosyltransferase
Apolipoproteins E
A class of protein components which can be found in several lipoproteins including HIGH-DENSITY LIPOPROTEINS; VERY-LOW-DENSITY LIPOPROTEINS; and CHYLOMICRONS. Synthesized in most organs, Apo E is important in the global transport of lipids and cholesterol throughout the body. Apo E is also a ligand for LDL receptors (RECEPTORS, LDL) that mediates the binding, internalization, and catabolism of lipoprotein particles in cells. There are several allelic isoforms (such as E2, E3, and E4). Deficiency or defects in Apo E are causes of HYPERLIPOPROTEINEMIA TYPE III.
Gene Deletion
Gene-Environment Interaction
DNA, Mitochondrial
Genes, p53
Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.
Disease Susceptibility
Sequence Alignment
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Mannose-Binding Lectin
A specific mannose-binding member of the collectin family of lectins. It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY.
DNA-Binding Proteins
Cytochrome P-450 CYP2D6
Receptors, Dopamine D4
Folic Acid
A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.
Prognosis
Molecular Epidemiology
Reference Values
Epoxide Hydrolases
Genetic Heterogeneity
The presence of apparently similar characters for which the genetic evidence indicates that different genes or different genetic mechanisms are involved in different pedigrees. In clinical settings genetic heterogeneity refers to the presence of a variety of genetic defects which cause the same disease, often due to mutations at different loci on the same gene, a finding common to many human diseases including ALZHEIMER DISEASE; CYSTIC FIBROSIS; LIPOPROTEIN LIPASE DEFICIENCY, FAMILIAL; and POLYCYSTIC KIDNEY DISEASES. (Rieger, et al., Glossary of Genetics: Classical and Molecular, 5th ed; Segen, Dictionary of Modern Medicine, 1992)
Repetitive Sequences, Nucleic Acid
Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).
Prospective Studies
Random Amplified Polymorphic DNA Technique
Technique that utilizes low-stringency polymerase chain reaction (PCR) amplification with single primers of arbitrary sequence to generate strain-specific arrays of anonymous DNA fragments. RAPD technique may be used to determine taxonomic identity, assess kinship relationships, analyze mixed genome samples, and create specific probes.
Spain
Recombination, Genetic
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
DNA Transposable Elements
Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.
African Americans
Hypertension
Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.
Deoxyribonuclease HpaII
Antigens, Human Platelet
5' Untranslated Regions
Biological Evolution
DNA Repair
The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.
P-Glycoprotein
A 170-kDa transmembrane glycoprotein from the superfamily of ATP-BINDING CASSETTE TRANSPORTERS. It serves as an ATP-dependent efflux pump for a variety of chemicals, including many ANTINEOPLASTIC AGENTS. Overexpression of this glycoprotein is associated with multidrug resistance (see DRUG RESISTANCE, MULTIPLE).
Tumor Necrosis Factor-alpha
Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.
Risk Assessment
Genome, Plant
The genetic complement of a plant (PLANTS) as represented in its DNA.
Czech Republic
Created 1 January 1993 as a result of the division of Czechoslovakia into the Czech Republic and Slovakia.
DNA Probes
Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.
Gene Dosage
The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.
DNA, Ribosomal
Sequence Homology, Nucleic Acid
Geography
Cluster Analysis
A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.
HLA-DRB1 Chains
Multigene Family
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
Aldosterone Synthase
A mitochondrial cytochrome P450 enzyme that catalyzes the 18-hydroxylation of steroids in the presence of molecular oxygen and NADPH-specific flavoprotein. This enzyme, encoded by CYP11B2 gene, is important in the conversion of CORTICOSTERONE to 18-hydroxycorticosterone and the subsequent conversion to ALDOSTERONE.
Carrier Proteins
Apolipoprotein C-III
A 9-kDa protein component of VERY-LOW-DENSITY LIPOPROTEINS and CHYLOMICRON REMNANTS. Apo C-III, synthesized in the liver, is an inhibitor of LIPOPROTEIN LIPASE. Apo C-III modulates the binding of chylomicron remnants and VLDL to receptors (RECEPTORS, LDL) thus decreases the uptake of triglyceride-rich particles by the liver cells and subsequent degradation. The normal Apo C-III is glycosylated. There are several polymorphic forms with varying amounts of SIALIC ACID (Apo C-III-0, Apo C-III-1, and Apo C-III-2).
Lymphotoxin-alpha
A tumor necrosis factor family member that is released by activated LYMPHOCYTES. Soluble lymphotoxin is specific for TUMOR NECROSIS FACTOR RECEPTOR TYPE I; TUMOR NECROSIS FACTOR RECEPTOR TYPE II; and TUMOR NECROSIS FACTOR RECEPTOR SUPERFAMILY, MEMBER 14. Lymphotoxin-alpha can form a membrane-bound heterodimer with LYMPHOTOXIN-BETA that has specificity for the LYMPHOTOXIN BETA RECEPTOR.
Cytochrome P-450 Enzyme System
A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.
Carcinoma, Squamous Cell
Protein Tyrosine Phosphatase, Non-Receptor Type 22
A subtype of non-receptor protein tyrosine phosphatases that is characterized by the presence of an N-terminal catalytic domain and a C-terminal PROLINE-rich domain. The phosphatase subtype is predominantly expressed in LYMPHOCYTES and plays a key role in the inhibition of downstream T-LYMPHOCYTE activation. Polymorphisms in the gene that encodes this phosphatase subtype are associated with a variety of AUTOIMMUNE DISEASES.
RNA, Messenger
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Sex Factors
Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.
Membrane Transport Proteins
Regression Analysis
Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.
Disease Progression
The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.
Transcription Factor 7-Like 2 Protein
A transcription factor that takes part in WNT signaling pathway. The activity of the protein is regulated via its interaction with BETA CATENIN. Transcription factor 7-like 2 protein plays an important role in the embryogenesis of the PANCREAS and ISLET CELLS.
Confidence Intervals
Receptor, Serotonin, 5-HT2A
A serotonin receptor subtype found widely distributed in peripheral tissues where it mediates the contractile responses of variety of tissues that contain SMOOTH MUSCLE. Selective 5-HT2A receptor antagonists include KETANSERIN. The 5-HT2A subtype is also located in BASAL GANGLIA and CEREBRAL CORTEX of the BRAIN where it mediates the effects of HALLUCINOGENS such as LSD.
Crosses, Genetic
Blotting, Southern
A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
Interleukin 1 Receptor Antagonist Protein
Ferredoxin-NADP Reductase
Steroid 17-alpha-Hydroxylase
A microsomal cytochrome P450 enzyme that catalyzes the 17-alpha-hydroxylation of progesterone or pregnenolone and subsequent cleavage of the residual two carbons at C17 in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP17 gene, generates precursors for glucocorticoid, androgen, and estrogen synthesis. Defects in CYP17 gene cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL) and abnormal sexual differentiation.
Coronary Artery Disease
Databases, Genetic
Databases devoted to knowledge about specific genes and gene products.
DNA, Ribosomal Spacer
Body Mass Index
An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)
Analysis of Variance
Lupus Erythematosus, Systemic
A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.
Oligonucleotide Array Sequence Analysis
Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.
Genome
Expressed Sequence Tags
Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.
Chromosome Inversion
Treatment Outcome
Genes
Chromosomes, Human, Pair 6
Reverse Transcriptase Polymerase Chain Reaction
Apolipoproteins A
Structural proteins of the alpha-lipoproteins (HIGH DENSITY LIPOPROTEINS), including APOLIPOPROTEIN A-I and APOLIPOPROTEIN A-II. They can modulate the activity of LECITHIN CHOLESTEROL ACYLTRANSFERASE. These apolipoproteins are low in atherosclerotic patients. They are either absent or present in extremely low plasma concentration in TANGIER DISEASE.
Quantitative Trait, Heritable
Sex Characteristics
Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.
Lipids
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
Arthritis, Rheumatoid
A chronic systemic disease, primarily of the joints, marked by inflammatory changes in the synovial membranes and articular structures, widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, and by atrophy and rarefaction of bony structures. Etiology is unknown, but autoimmune mechanisms have been implicated.
Receptors, IgG
Specific molecular sites on the surface of various cells, including B-lymphocytes and macrophages, that combine with IMMUNOGLOBULIN Gs. Three subclasses exist: Fc gamma RI (the CD64 antigen, a low affinity receptor), Fc gamma RII (the CD32 antigen, a high affinity receptor), and Fc gamma RIII (the CD16 antigen, a low affinity receptor).
Membrane Proteins
Interleukin-10
A cytokine produced by a variety of cell types, including T-LYMPHOCYTES; MONOCYTES; DENDRITIC CELLS; and EPITHELIAL CELLS that exerts a variety of effects on immunoregulation and INFLAMMATION. Interleukin-10 combines with itself to form a homodimeric molecule that is the biologically active form of the protein.