Glossary of Terms
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What is DNA?
DNA (deoxyribonucleic acid) encodes information to make each of us who we are. DNA is made up of four nucleotides: adenine (A), cytosine (C), guanine (G), and thymine (T) in two strands. The order of these four nucleotides is different for each person and each person has more than 3 billion nucleotides making up their body. DNA is located almost everywhere in the body except inside red blood cells. You are born with your DNA and it does not change significantly during your life.
Regions of DNA called introns contain repeats of nucleotide patterns while exons contain genes. Genes are lengths of DNA that encode a message to make a protein. Proteins do all of the work in the body. Proteins can be enzymes, regulation factors, or structural components within the body.
Many of our tests look at a specific DNA sequences in the body that make up a gene. In many cases research has shown that a single nucleotide change in a gene can influence how your body reacts to substances you consume (for example ethanol, caffeine, or pharmaceutical compounds such as albuterol).
What is RNA?
RNA (ribonucleic acid) is an intermediary between DNA and protein.
What is a gene?
Genes are lengths of DNA that encode a message to make a protein.
What is a protein?
Proteins perform the daily functions to keep our bodies running. Proteins can be enzymes, regulation factors, or structural components within the body.
What is an allele?
An allele is a region of DNA, often encoding a gene, that is inherited from either the mother or the father.
What is a chromosome?
A chromosome is a bundle of DNA. Humans have 23 chromosomes: chromosomes 1 through 21 and either two X chromosomes (female), or one X and one Y chromosome (male).
What is homozygous?
Homozygous means that a person has two identical copies of an allele.
What is heterozygous?
Heterozygous means that a person has two different copies of an allele.
What is phenotype and genotype?
A phenotype is an observable characteristic while a genotype is the actual gene sequence which may or may not result in an observable characteristic.
What is dominant?
A dominant phenotype means that the phenotype displays if the person has two copies of the dominant allele or if they have one copy of the dominant allele and one copy of the recessive allele. For example, (GIVE EYE COLOR EXAMPLE or something similar).
What is recessive?
A recessive phenotype means that the phenotype displays only when a person has two copies of the recessive allele. For example (GIVE THE OPPOSITE CASE AS ABOVE)
What is a nucleotide?
A nucleotide is a compound made up of a base, a sugar, and a phosphate group. DNA is made up of four nucleotides adenine (A), cytosine (C), guanine (G), and thymine (T), while RNA is made up of adenine (A), cytosine (C), guanine (G), and uracil (U).
What is qRT PCR?
qRT PCR (quantitative real time polymerase chain reaction) is a version of PCR in which the DNA being amplified can be seen in real time. Fluorescent dyes attached to the newly synthesized DNA are detected over time so that as more and more DNA accumulates more fluorescence is detected. This precise detection of product can be used to determine the exact amount of DNA present in the original sample, for example a sample submitted by one of our customers.
What is PCR?
PCR (polymerase chain reaction) is a process in which a small amount of DNA is amplified into a much larger amount (by as much as 240 times) by enzymes that synthesize DNA at high temperatures. The temperature is regulated in three stages that make up each synthesis cycle. Many similar cycles are run in order to exponentially increase the amount of DNA.
What is allele discrimination?
Allelic discrimination is a technique that allows detection of a region of DNA in which there is a single nucleotide difference or single nucleotide polymorphism (SNP) between each of the alleles inherited from a person’s parents.
What is a SNP?
A SNP (single nucleotide polymorphism) is a single nucleotide change in the DNA. Often SNPs occur in genes and change the way a protein functions, creating a phenotype.
What is a positive control?
A positive control is a known sample that gives a positive result. Controls are used as a quality control measure to ensure a test is working properly.
What is a negative control?
A negative control is a known sample that gives a negative result. Controls are used as a quality control measure to ensure a test is working properly.
What is the human genome?
The human genome is composed of 21 autosomal chromosomes and 2 sex chromosomes.
What are autosomal chromosomes?
Autosomal chromosomes are non-sex chromosomes that are present in both sexes.
What is a sex chromosome?
In humans the sex chromosomes are the X and Y chromosome. Females have two X chromosomes while males have one X and one Y chromosome.