DNA Lady
What's all this DNA stuff? Here are some useful terms you may hear when you are having a DNA test performed to determine a family or biological relationship.
Apoptosis - the programmed death of cells. It is a mechanism of the organism to maintain a relative constance and normal number of cells. It also includes a cascade of biological processes tht result to the death of a cell, when it is seriously damaged or infected by a virus.
Adipocyte is the main type of cell that compose adipose tissue and are also known as fat cells, or lipocytes. Their main function is to store energy in the form of fat.
DNA - Deoxyribonucleic Acid - this is the biologic substance found in the nucleus of cells of all human beings. DNA, inherited from a biological parent, is the basis of our heredity or ancestry. DNA contains the code from which all our physical characteristics are determined as well as the instructions for making living organisms. A single strand of DNA is composed of four different chemicals - Adenine (A), Thymine (T), Cytosine (C) and Guanine (G).
Chromosome - these are groups of the DNA molecules found in a cell that are held together by the above four proteins.(ATCG) Different kinds of organisms have different numbers of chromosomes but all are created at conception, arranged in pairs and consist of one set of chromosomes inherited from the mother (mtDNA) and the other from the father (Y-DNA). Humans have 23 sets of chromosomes - one pair will decide the sex of the child (XX)Female and (XY)Male. These are the thread-like symbols you see in your Biology books.
Y-Chromosome - the genetic material passed from father to son at conception. The Y-chromosome is passed unchanged except for the rare defining mutations.
Buccal Swab - the method by which a majority of DNA collections are performed today. A large cotton tipped swab is swabbed against the inside of the cheek using gentle pressure in order to collect enough cells (not saliva) to amplify under the PCR method.
Haplogroups - anthropologists study of population genetics and the mutations that occurred during migration and geographic manifestations. The use of Short Tandem Repeat markers predicts or estimates one's Haplogroup to be within18 categories and 80 additional sub-groups and clades. The STR marker is only an estimate.
Mitochondrial DNA - the genetic material passed from mother to all of her offspring, save for a rare mutation that may occur in some instances.
Mutation - a genetic inconsistency occurring naturally in all living organisms. This is a permanent structural alteration in our DNA. Mutations, may or may not, improve an organism's chance of survival. In speaking of genetic mutations, the reference is no way relates to abnormal medical conditions or gene functions.
Genotype - describes the constitution of a gene (the type of the gene). It refers each time to a specific gene, under investigation, describing the alleles that the gene contains. It often refers to the pair of the nucleotides found at a specific position of the DNA sequence.
Genetic Marker - a segment of DNA with an identifiable physical location on a chromosome and whose inheritance can be followed. A marker can be a gene, or it can be some section of DNA with no known function. Because DNA segments that lie near each other on a chromosome tend to be inherited together, markers are often used as indirect ways of tracking the inheritance pattern of a gene that has not yet been identified, but whose approximate location is known.
Allele - one of the forms of a gene at a particular location on a chromosome. Different alleles produce various inherited characteristics, such as eye color, hair color or blood type. Individuals have dominant and recessive forms of alleles. Do not use the on-line eye color charts as proof of biological relationships - these are absolutely not reliable as they do not take into consideration naturally occurring mutations that have been passed on.
Amino Acid - components of proteins. Some are synthesized by the body (non essential amino acids) and others must e obtained through diet (essential amino acids)
Carbohydrate - is a compound of cargon, hydrogen an doxygen. It is an important source of energy found in food.
Cholesterol is the waxy, fat-like substance essential for the structure of cell membrane. It is also a component of certain hormones and some Vitamins and is transported with lipproteins through blood circulation.
Chromatin is the combination of DNA an dproteins which when condensed makes up chomosomes.
Enzymes is a protein that controls biochemical reactions, resulting in either production or inactivation of substances in cells.
Glucose is a very important carbohydrate in biological systems. It is used by cells as a course of energy and is also an intermediate of metabolism.
Homeostasis is a state of equilibrium (balance) or the tendency to reach equilibrium. It is the ability of a living organism to regulate its internal environment in order to maintain a stable condition.
Homocysteine is an amino acid, important for the production of another amino acid call Cysteine. Homocysteine metabolism and maintenance of normal levels is crucial for the health, as elevated homocysteine levels in blood is associated primarily with problems of the cardiovascular system.
Mutagen is an agent which can cause change in the genetic material of an organism.
Oxidative stress is caused in cells due to their reduced ability to fight against oxidative factors, which are substances like peroxides and free radicals. Whether caused by normal functions of cells, or produced by environmental toxins - both can have toxic effects as t hey can damage seriously the components of cells (proteins, lipids, DNA).
Pharmacogenomics is the field of Pharmacology and Genetics, which investigates how the DNA of individuals affects their response to drugs. Based on DNA testing, it aims to identify which drugs have increased efficacy or cause reduced toxicity to an individual.
Polymerase Chain Reaction (PCR) - this is the process by which copies of our specific DNA segments are made from a DNA sample. In a DNA Paternity test, DNA are amplified so they can be analyzed to determine whether the alleged father and tested child have common loci (position of a gene on a chromosome), supporting the existence of a biological relationship. This process has been extensively used for paternity testing. Large databases have been accumulated for accurate DNA analysis. This large database enables paternity testing via PCR to have the highest power of exclusion.
Restriction Fragment Length Polymorphism (RFLP) - this is process that relies on the genetic uniqueness of an individuals to determine a biological relationship to another individual. No two persons (except for identical twins) have the same DNA. A DNA sample is treated with specific enzymes to create fragments. The size of the fragments are then measured and statistically analyzed. If too many fragments do not have a match, the a biological relationship is considered excluded or not possible. This technique increased the power of the exclusion of biological relationships to 99.99 % and greater.
VO2 - maximal oxygen consumption, describing the amount of oxygen transported and used during physicla exercise of individuals. It is an important factor for physical fitness.
Xenobiotic is a chemical found in an organism bit it is not normally produced by it nor obtrain by diet. Drugs and antibiotics are examples of xenobiotics.
History of DNA Testing for Paternity
1920s Blood Type - identifying one blood type only and ability to exclude only 30% of the population - not useful or conclusive in proving paternity.
1930s Blood Groups - measured inherited proteins in the blood and ability to exclude 40% of the population - not useful or conclusive in proving paternity.
1970s HLA Typing - cannot differentiate between related alleged fathers (brothers, uncles, grandfathers) and but had the ability to exclude 80% of the population. The test required a large amount of blood from all participants and was therefore not used on infants younger than 6 months.
1980s RFLP - ability to exclude 99.99% of the populations
1990s PCR - ability to exclude 99.99% of the population and oral swab method preferred. This is the method by which we perform our DNA Tests in New Jersey *732-632-8830*
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