Genetic Education
Benign:
A variant in a gene that is not associated with a known condition associated with other variants in that gene.
Carrier:
An individual who is heterozygous for a genotype has been linked to a certain condition. They carry one variant that is associated with the condition, however, it does not mean that they have the condition.
Increased/Decreased:
At times your report might say that something is “increased” or “decreased”. Be sure not to assume these results indicate you are high, low, or deficient in a certain nutrient. The only way to determine this is to consult with your physician and get a specific blood test designed to assess a specific nutrient. This genetic test can only assess your risk; a blood test or hair mineral tissue analysis is what can assess your actual levels.
Increased Risk:
For common diseases, the presence of a high-risk allele may only mildly increase the chance of disease. Just because a result says there is an increased risk does not mean you will have the condition mentioned. Many times, the risk is very slight and dependent on many factors. Again, it is important to look at the report as a whole to weigh the major factors or multiple associations on the report.
“Pathogenic”
The genotype is believed to account for the symptoms or there is a probable cause that the variation leads to a certain disease or trait.
“Probable-Pathogenic”
The variant has been previously associated with the condition. Often, there is insufficient evidence that a variant is a definite cause for symptoms.
“Likely Pathogenic”
The variant most likely has a harmful effect. If the person is showing symptoms of the associated disease, then it can help aid in finding the proper testing needed to verify condition.
Uncertain-Significance:
Variant of Uncertain Significance (VUS) has an uncertain relationship to disease. There are several reasons why variants are classified as VUS, such as: The effect of the specific genetic alteration on gene function is not known; There is insufficient genetic data to definitively confirm that the variant is associated with risk of developing the disease; The patient is unaffected and has no symptoms, or different symptoms than those expected based on the variant found. As more data accumulates over time, a VUS may be reclassified to likely pathogenic or likely benign. We still provide this information in case a person's symptoms line up with the disorder for a possible answer needed.
Negative or “normal”:
A negative or normal result means you do not have a change in the gene(s) tested. Usually, a negative test result is good news, but there are some limitations. Some clinical conditions can be caused by more than one gene and the laboratory may not have tested for all of these genes. Other conditions may be caused by different types of changes within the same gene, but the laboratory may not test for all the types of changes. This means a negative test does not always rule out the presence of every gene change that could cause a disease. You still might have a change in a gene, even if your test is normal.
ANY RISK FINDINGS NEED TO BE CONFIRMED BY ADDITIONAL TESTING OR SYMPTOMS TO SEE IF THE RESULT IS VALID! WE USE CLINVAR, WHICH CAN SAY A RESULT IS A RISK BASED ON LOCATION, BUT ADDITIONAL STUDIES MAY NEED TO BE DONE TO CONFIRM IN THE FUTURE. WE STILL LIKE TO PROVIDE THESE RESULTS SO IT MAY HELP SOMEONE FIND A POSSIBLE RISK TO FURTHER RESEARCH!
ClinVar is a robust online resource that catalogs the classification of specific genetic variants, submitted by genetic testing laboratories and experts.
Penetrance:
A characteristic of a genotype; it refers to the likelihood that a clinical condition will occur when a particular genotype is present.
PGX:
PGX is a shortened term for Pharmacogenomics, which can tell you how pharmaceuticals interact with your genes.
Wild-Type:
Having two normal (ancestral) alleles is known as the wild type. It will be represented as (-/-) on your report.
Heterozygous:
The situation in which one allele is mutated and the second is normal (wild-type) is referred to as heterozygous. It will be represented as (-/+) on your report.
Homozygous:
A combination of the same two mutations in each of the alleles is defined as homozygous. It is represented as (+/+) on your report.
Compound Heterozygous
When you have two heterozygous genotypes that have been correlated to react with each other, sometimes creating symptoms of a homozygous genotype.
Haplotypes:
A combination of different genotypes that are associated with a certain reaction.
Deletions:
When alleles are absent because of a deletion in your DNA code. It is represented with a “D” or “DD” on your report.
Insertions:
When alleles are added or inserted into your DNA code. It is represented with an “I” or “II” on your report.
Hemizygous:
For most of the X chromosome genes in males, as they only have one, the report may only show one allele.
X-linked Conditions:
Females have two X chromosomes, and males have one X and one Y chromosome. For X-linked conditions, women are typically carriers and have fewer if any symptoms, while males are affected. Males are at an increased risk of disease because they only have one copy of the X chromosome and therefore only one copy of the many genes located on the X chromosome. If one of these genes is not working, there is not another copy to compensate.
A female carrier for an X-linked recessive disease has a 50% chance of passing on the variant in each pregnancy. Sons that inherit the variant would be expected to be affected with the condition, while daughters with the variant are less likely to exhibit symptoms.
A male with an X-linked condition will pass on the variant to each of his daughters (because the variant is on his X chromosome, which he passes on to each female child) and none of his sons (because each son receives only a Y chromosome from his father).
Autosomal Dominant:
In an autosomal dominant disease, if you get the abnormal gene from only one parent, you can get the disease. Often, one of the parents may also have the disease. Dominant inheritance means an abnormal gene from one parent can cause disease. In other words, you only need 1 “bad” copy to cause the disorder.
Autosomal recessive:
Genetic conditions occurring when mutations are present in both copies of a given gene (the person is homozygous for a mutation, or carries two different mutations of the same gene, a state referred to as compound heterozygosity). In other words, you need 2 “bad” copies to cause the disorder. Parents may each carry 1 bad copy and pass those on to their children and neither parent has the disease, they are just carriers. A carrier for a recessive condition is asymptomatic and has a pathogenic genetic variant in just one of their two copies of the associated gene. Parents that are both carriers of the same recessive condition have a 25% chance that a child will inherit the pathogenic variant from both parents and be affected by the condition. There is a 50% chance that the child will inherit a single pathogenic variant from one parent and will also be an asymptomatic carrier. There is a 25% chance that the child will inherit neither variant and will not be affected or a carrier.
Cell:
A small chemical filled membrane-bound compartment; they are the subunit of all living things, including humans.
DNA (Deoxyribonucleic Acid):
A large molecule that carries the genetic information needed to operate a cell, make tissues and control organ systems.
Enzyme:
A protein that speeds up a biochemical reaction. Enzymes are critical to cell functions.
Gene:
A subunit of DNA that contains the message for a cell product, typically some type of protein such as an enzyme. Humans have 20,000-25,000 genes.
Genetic:
A trait or condition determined by one or more genes.
Genetic variant:
A change in the DNA sequence as compared to a reference sequence that may or may not have an impact on protein function or disease state. Terms such as mutation and polymorphism have been largely replaced by ‘variant’ to simplify terminology.
De novo (variant):
An alteration in a gene that is present for the first time in one family member as a result of a mutation in a germ cell (egg or sperm) of one of the parents, or a mutation that arises in the fertilized egg itself during early embryogenesis. Also called a new mutation.
Genome:
The entire set of genetic instructions in a cell consisting of 23 pairs of chromosomes. It is in the nucleus and small chromosome found in the cells’ mitochondria. Each set of 23 chromosomes contains approximately 3.1 billion bases of DNA sequence.
Phenotype:
A result of the expression of your genes that shows up clinically from a genotype.
Polymorphism:
Alleles with a high population frequency, typically defined as >1%, are referred to as polymorphisms. These small differences in DNA sequence, or genetic variation, may or may not affect gene function. However, some common variants can interfere with a biological process, leading to illness, typically in combination with other factors. Such conditions are considered to have a genetic basis, and are typically classified as “common complex” disorders.
Protein:
A large complex molecule that is essential to the body structure, function and regulation. Examples include: hormones, enzymes, and antibodies. Proteins are determined by the DNA sequences within genes.
Single nucleotide polymorphism (SNP):
DNA sequence variations with an altered single nucleotide (adenine (A), thymine (T), cytosine (C), or guanine (G)) in your genome sequence. These represent A,T, C, G on your genotype reports.
Mutations:
Changes in the DNA sequence of single genes that can cause thousands of diseases. A gene can mutate in several ways which result in an altered protein that is unable to perform a normal function. The most common causes a “misspelling” in a single base in the DNA. Other include the loss (deletion) or gain (duplication or insertion) of single or multiple bases (s). The altered protein product may still retain some normal function but at a reduced capacity. In other cases, the protein may be totally disabled by the mutation or gain an entirely new, but damaging, function. The outcome depends on how it alters a protein’s function and how vital that protein is to survival.
Colors on your genotype report and the charts below:
The colors are simply a way to easily identify each of the genotypes.
Green is (-/-) Wild-type
Yellow is (-/+) Heterozygous
Red is (+/+) Homozygous