DNA Terms
AABB
Previously recognized as the American Association of Blood Banks, this entity establishes guidelines for blood transfusion services and related biologic treatments, encompassing DNA testing for confirming personal identity.
Affidavit
Evidence that is acceptable in a court of law.
Allele
An allele is one of two or more versions of a gene that are found at the same place on a chromosome. Alleles can vary slightly in their sequence of DNA bases.
Alleged Father:
An “alleged father” is a term used to describe a man who is claimed to be, or who claims himself to be, the biological father of a child, but whose paternity has not yet been legally established. This term is often used in legal contexts, such as child support cases, custody disputes, or when determining inheritance rights, where there may be a question about the individual’s parental status.
Autosome:
An autosome is any chromosome that is not a sex chromosome. Humans have 46 chromosomes in each cell, consisting of 22 pairs of autosomes and one pair of sex chromosomes (which are the X and Y chromosomes). The autosomes are numbered from 1 to 22, typically in descending order based on their size. They contain the vast majority of an individual’s genetic information, including genes that determine characteristics unrelated to sex, such as eye color, height, and skin tone.
Avuncular:
An avuncular DNA test is a type of genetic testing used to determine the likelihood that an individual is the biological aunt or uncle of a child, hence the term “avuncular,” which is derived from the Latin word “avunculus” meaning “uncle.” This test compares an individual’s DNA with that of a possible niece or nephew to assess the likelihood of a biological relationship.
Biological Child:
A biological child is an offspring who is genetically related to both of their parents. This child inherits DNA, physical characteristics, and sometimes even behavioral traits from their biological mother and father through sexual reproduction.
Biological Father:
A biological father is the male who has contributed half of the genetic material to an offspring through the process of fertilization.
Buccal Cheek Swab:
A buccal swab is a way to collect DNA from the cells on the inside of a person’s cheek. The term “buccal” refers to the cheek area. This method is non-invasive and simple, often used in genetic testing, forensics, and paternity tests.
Chain of Custody:
In legal contexts, it is a process used to maintain and document the chronological history of the evidence. The chain of custody is important in child custody and criminal cases, where the evidence must be proven to have been handled and preserved in a manner that ensures its integrity from the time it is collected until it is presented in a court of law.
Child Support:
Child support is a financial obligation paid by one parent to another, typically following a divorce or separation, to assist with the costs associated with raising their child or children. The purpose of child support is to ensure that children continue to receive adequate care and financial support from both parents, even if they are no longer living together as a family unit.
Chromosome:
Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA), which is passed from parents to offspring during reproduction.
Court Admissible
Proof/evidence that is admissible in court
Collection Site:
A designated facility where DNA samples are collected for DNA testing.
CRBA
CRBA (Consular Report of a Birth Abroad) is a document issued by a U.S. embassy or consulate to a child born abroad to U.S. citizen parents. It serves as proof of the child’s U.S. citizenship and is equivalent to a birth certificate issued in the United States.
The CRBA is an important document for establishing the child’s U.S. citizenship and obtaining other documents such as a U.S. passport. It is typically obtained by the child’s parents or legal guardians through the nearest U.S. embassy or consulate.
Custodial Parent:
The term “custodial parent” typically refers to the parent with whom a child lives for the majority of the time following a separation or divorce.
DNA Extraction:
DNA extraction is the process of obtaining pure DNA from a sample, which may consist of cells or tissues from organisms like plants, animals, bacteria, or viruses. The purpose of DNA extraction is to isolate the DNA from other cellular components such as proteins, lipids, and RNA.
DNA Fingerprinting:
DNA fingerprinting, also known as DNA profiling, is a technique used to identify and analyze the unique genetic makeup of an individual. It involves comparing certain regions of an individual’s DNA that are highly variable among individuals to create a unique genetic profile.
This profile can be used for various purposes, including identifying individuals, determining genetic relationships, and solving crimes.
DNA Profile:
A DNA profile, also known as a DNA fingerprint, is a unique pattern of DNA sequences that can be used to identify an individual among others.
Dizygotic Twin:
Dizygotic twins, commonly known as fraternal twins or non-identical twins, are siblings born from separate eggs that were fertilized by different sperm cells. This occurs when a woman releases two eggs during her menstrual cycle, and both eggs are fertilized, each by a distinct sperm cell.
Exclusion:
Dizygotic twins, commonly known as fraternal twins or non-identical twins, are siblings born from separate eggs that were fertilized by different sperm cells. This occurs when a woman releases two eggs during her menstrual cycle, and both eggs are fertilized, each by a distinct sperm cell.
Epigenetic Modification:
Epigenetic modification refers to a set of reversible, heritable changes in gene function or expression that occur without altering the underlying DNA sequence. These modifications can affect how cells “read” genes and can have profound effects on cellular function and organismal development. Epigenetic modifications can be influenced by various factors, including environmental cues, developmental stages, and disease states
Fraternal Twin:
Fraternal twins, also known as dizygotic or non-identical twins, are siblings who share the same birth date or birth period (such as within a few minutes or hours if born on different dates) but are the result of two separately fertilized eggs. Unlike identical twins, who originate from a single fertilized egg that splits into two embryos, fraternal twins come from two different eggs fertilized by two different sperm cells.
Gene:
A unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
Grandparent:
The parent of one’s father or mother; a person’s grandmother or grandfather.
HLA:
Human Leukocyte Antigens (HLA) are a crucial component of our immune system, playing a pivotal role in its ability to distinguish between self and non-self entities. These antigens are essentially genes located in what is known as the major histocompatibility complexes (MHC).
Their primary function is to help code for proteins that are integral to this self/non-self differentiation process, a critical mechanism that ensures the immune system correctly identifies and combats pathogens such as viruses and bacteria, without attacking the body’s own cells.
Immigrant Visa:
An immigrant visa is a type of visa that allows individuals to enter and reside in a foreign country with the intention of becoming permanent residents or citizens. It is typically granted to individuals who wish to immigrate to another country for various reasons, such as employment, family reunification, or seeking refuge.
Inclusion:
In DNA testing, the determination that a person is the biological parent or relative of another person.
Kinship:
The state of being related to others by blood or family ties.
Loci:
(plural of locus) – Specific, fixed positions on chromosomes where genes or genetic markers are located.
Maternal:
Relating to a mother; of or inherited from one’s mother.
Matrilineal:
Tracing descent through the maternal line.
Mitochondrial DNA:
The small circular chromosome found inside mitochondria, which are organelles located in the cytoplasm of eukaryotic cells. It is passed down from mothers to their offspring.
Molecule:
The smallest particle of a substance that retains the chemical properties of that substance, consisting of one or more atoms.
Non-custodial
Refers to a parent who does not have primary custody of a child.
Paternity
Paternity refers to the legal and biological relationship between a father and his child.
Paternity Index (PI):
Is a statistical measure used in genetic testing to evaluate the probability of paternity.
It compares the likelihood that the alleged father has contributed a particular allele (version of a gene) to a child versus the likelihood that a randomly selected unrelated man from the same population could have contributed the same allele.
PCR:
PCR stands for Polymerase Chain Reaction. It is a common laboratory technique used to amplify a specific segment of DNA through a series of temperature changes and enzyme reactions.
Random Man:
is a statistical measure used in genetic testing to evaluate the probability of paternity.
It compares the likelihood that the alleged father has contributed a particular allele (version of a gene) to a child versus the likelihood that a randomly selected unrelated man from the same population could have contributed the same allele.
Relative:
A person connected by blood or marriage to another person.
Request For Evidence (RFE):
A Request for Evidence (RFE) is an office action issued to petitioners by the United States Citizenship and Immigration Services (USCIS) when insufficient evidence is submitted during the visa application
RFLP:
Restriction Fragment Length Polymorphism (RFLP) is a technique used in molecular biology to analyze genetic variations. It involves cutting DNA into fragments using restriction enzymes and separating these fragments by size through gel electrophoresis.
The resulting patterns of DNA fragments can be used to identify differences in the genetic material among individuals.
Self Collection:
The process of an individual collecting their own biological samples, such as DNA via a buccal swab, often for genetic testing.
Sex Chromosome:
A type of chromosome involved in the determination of the sex and the development of sexual characteristics. In humans, these are the X and Y chromosomes.
Short tandem repeats are sequences of DNA bases that are repeated multiple times in a row.
They are commonly used in DNA testing because they vary widely between individuals, making them useful for identification and relationship testing.
The degree of similarity of the alleles for a trait in an organism. For example, monozygotic twins have identical alleles for all their genes, while dizygotic twins do not.