TERM IN GENETIC MEDICINE WE SHOULD RECOGNIZE

Bioinformatician
A person that uses mathematics and statistics to interpret the large amount of computer-generated data from genetic/genomic research or clinical studies.
Bioinformatics
A modern field of science that combines biology, computer science, and information technology. Bioinformatics is essential to better understanding and analyzing the large amounts of genetic and genomics data that can result from research studies. Complex bioinformatics analysis is also needed to interpret an Individual Genome Sequence (IGS).
Chromosome
DNA is organized into structures known as chromosomes. These are like volumes in a genomic encyclopedia. The human genome is comprised of 23 pairs of chromosomes.
Copy Number Variation
Sometimes several copies of a gene, segment of a gene, or stretch of DNA are present in the genome sequence. When the number of copies is different for one individual compared to another, this is known as copy number variation (CNV).
dbSNP
The Single Nucleotide Polymorphism Database (dbSNP) is a free online resource that contains all identified genetic variations for a variety of species, including human.
Deletion
A change in the DNA sequence in which one or more DNA bases are removed.
Dominant Disorder
An inherited disorder that results when only one copy of the gene is altered. Individuals with a dominant disorder have one gene copy that makes a normal protein and one gene copy that makes an abnormal protein. There is a 50-50 chance that an affected individual will pass on a dominant disorder to each of their children.
DNA
Deoxyribonucleic acid. A DNA base, or nucleotide, is the primary structure that makes up a DNA molecule. There are four different types of DNA bases; each represented by one of four letters (A, C, G, T). These are the letters that make the words of your genetic story. The human genome is estimated to contain more than three billion DNA base pairs.
DNA Sequencing
A method for determining the precise order of DNA bases, or nucleotides, in the genome.
Duplication
A change in the DNA sequence in which one or more bases are copied.
Expressivity
Expressivity is a concept that describes how an individual with a particular genetic condition may be affected. In particular, it refers to which symptoms may develop and how severe or mild those symptoms may be.
Gene
A gene is a defined segment of DNA that contains important genetic information and is inherited as a unit. The information within genes provides instructions on how to make proteins and other important biologic substances for the body. Think of genes as chapters or entries within the volumes of your genome encyclopedia. The human genome contains 20,000–25,000 distinct genes.
Genetic Counselor
A professional specializing in the communication of genetic information to patients and families. He or she often works closely with medical geneticists or doctors. A genetic counselor is trained in genetic risk assessment and counseling and can help support you and your doctor when making decisions about your health. You can locate a genetic counselor through the National Society of Genetic Counselors.
Genetic Disorder
A disease caused by a particular DNA change that is passed from parent to child. Also known as an inherited disorder.
Genetic (or Genomic) Sequence
A series of DNA bases (represented by letters). Think of your entire genomic sequence as a set of encyclopedias. Your body uses the information coded in your genome encyclopedia to build and run your body. The human genome sequence is made up of more than three billion DNA base pairs contained within 23 chromosomes.
Genetic Variation
Differences that exist from one individual’s DNA sequence to another. These are, in effect, what make you uniquely you.
Genome
Your complete DNA sequence, including the proteins required to read and maintain it as well as the many particles that provide its structure. It contains genes and more, such as segments of DNA that switch genes on and off. Consider your genome to be a library that houses your genome encyclopedia. Everything in your genome library has a purpose and researchers are still learning about each role.
Genome Risk Profile
An analysis of some parts of your genome by looking at a specific set of defined locations representing known locations of DNA variations in the genome. This type of testing service can provide information about things such as your risk for common diseases, carrier status for common recessive DNA changes, and insights on your genetic ancestry. Companies scan pre-defined locations in the genome for a “snapshot” look that is based on the most current discoveries at that time. As new discoveries are made, new analysis, or updates need to be performed.
Genotype
A particular DNA change, DNA sequence, or pattern of DNA changes in your genome. Your genotype can be used to identify you. In some cases, a specific genotype causes a specific physical characteristic or trait (phenotype).
Genotyping
The process of determining the genotype of a sample.
GINA (Genetic Information Nondiscrimination Act)—U.S. only
On May 21, 2008 the United States Congress passed GINA (Genetic Information Nondiscrimination Act). This act provides protection from improper use of your genetic information by health insurance companies and employers.
Individual Genome Sequencing (IGS)
Illumina’s personal genome sequencing service. It provides a way for people to obtain their DNA sequence for personal use. Illumina Clinical Services Laboratory is proud to be the first CLIA-certified, CAP-accredited laboratory to offer IGS. IGS has been developed using the highest standards by a team of licensed professionals, an external ethics advisory board, and experts from a variety of areas. The comprehensive nature of this testing represents a new step in the practice of medicine, in which the results will continue to be meaningful and relevant throughout a person’s lifetime.
Inherited Disease
A disease caused by a particular DNA change that is passed from parent to child. Also known as a genetic disorder.
Insertion
A change in the DNA sequence in which one or more bases are added or inserted.
Medical Geneticist
A medical doctor who evaluates patients for genetic concerns. This consultation may include a medical history, family history, and a detailed physical examination. Geneticists frequently work with genetic counselors. You can locate a medical geneticist through the American Board of Medical Genetics.
Nucleotide
See DNA.
Penetrance
Penetrance is a concept that describes whether an individual who has a gene change associated with a genetic disorder will develop any symptoms associated with the disorder. For example, if a condition has 20% penetrance, then a person who inherits the particular gene change will have a 20% chance of developing symptoms of the disorder in their lifetime.
Phenotype
A physical, health, or behavioral characteristic or trait. It is essentially the physical and psychological self, including health conditions we may develop. In some cases, a specific phenotype can be linked to specific genetic information.
Recessive Disorder
An inherited genetic disorder that requires both copies of a gene to be altered in such a way that neither of them work properly. The result is that the individual with a recessive condition does not produce the needed gene product or protein.
SNP
Single nucleotide polymorphism. A site in the genome where one DNA base letter is often substituted for another. SNPs may be linked to characteristics and/or disease risks. They are frequently used in genome risk profiling services.
Substitution
A change in the DNA sequence in which one base is substituted for another.
Translocation
A change in the DNA sequence in which several DNA bases are cut (deleted) from one location and pasted (inserted) into another. A balanced translocation means that the total amount of DNA remains the same even though it is in a different location. An unbalanced translocation means that some DNA has been lost and/or duplicated during the cut-and-paste process.