Genomic Enterprise

 
Blockbuster drug  A blockbuster drug is a drug generating more than $1 billion of revenue for its owner each year. The search for blockbusters has been the foundation of the R&D strategy adopted by big biotechnology and pharmaceutical companies. New advances in genomics / epigenomics and the promise of personalized medicine are likely to fragment the pharmaceutical market into subgroups of patients and blockbusters will become rare.

 
Cancer is a genetic and epigenetic disease in which a group of cells has uncontrolled growth and invasion properties. Malignant  cancers are different from benign tumors which are self-limited, do not invade or metastasize. The majority of the cancers form a solid mass, but others, such as leukemia, do not.   

 
Clinical utility  An assessment of the risks and benefits resulting from using a particular test and the likelihood that the test will lead to an improved overall outcome (in case of disease such as cancer).

Clinical validity The accuracy with which a test identifies or predicts a patient’s clinical status. For genetic testing, the relevance of a particular gene to a disease can be assessed by genome-disease association studies and the accuracy of a test is evaluated in terms of its specificity and sensitivity. Recently, genome-wide validity test have been largely applied in genetic research.

 
Clinical trials A clinical trial is a research study in human volunteers to answer specific health questions. Carefully conducted clinical trials are the safest and fastest way to find treatments that work in people, and new ways to improve health.

Complex disease Any disease  that does not exhibit classical inheritance patterns attributable to a single gene. In most cases, multiple genetic and environmental factors (such as epigenetic and epigenomic) are involved (examples of complex diseases are cancer and diabetis).

 
Chromosomes The structures within cells that carry the genetic information in the form of DNA. Each chromosome is composed of a single, long molecule of DNA, complexed with specific proteins. Humans have 22 pairs of autosomes and 2 sex chromosomes. One member of each pair of chromosomes is inherited from the father, and the other one from the mother.

 
Diagnostic test In-depth evaluation with a relatively narrow scope of analysis, aimed at identification of a specific condition.

 
Epigenetics Any change in the DNA molecule that does not change the sequence of bases but can change the molecular structure. In more general terms, an epigenetic factor is something that can change the phenotype without changing the genotype. There are two main epigenetic changes in the DNA molecule - DNA methylation and histone modifications.

 
Epigenome  Description of all the epigenetic modifications across the whole genome. Unlike the genome (DNA sequence), different cells within an organism have different epigenomes that may change with time in response to environmental modifications and lifestyle.

 
Gene  A part of the DNA molecule of a chromosome which encodes (directs the synthesis of) functional products such as proteins and non-coding RNAs.

Genetic counseling is the process by which patients or relatives, at risk of an inherited disorder, are advised of the consequences and nature of the disorder, the probability of developing or transmitting it, and the options open to them in management and family planning in order to prevent, avoid or ameliorate it. This complex process can be seen from diagnostic (the actual estimation of risk) and supportive aspects.

 
Gene expression The process by which the information in the DNA sequence of a gene is transcribed into messenger RNA.

 
Genetic screening Carrying out a genetic test on a whole unselected population, or on all the members of a subset of the population (for example, people from a particular ethnic group, or pregnant women, or newborn infants).

 
Genetic test A test to detect the presence or absence of changes in a particular gene or chromosome in the genome.

 
Genome Complete genetic sequence of the DNA for an organism.

 
Genotype The specific genetic constitution of an individual (based on the DNA sequence).

 
Histones  Set of proteins that form a scaffold around which chromosomal DNA is wound, in order to compact it inside the cell. Chemical modification of the histones such as acetylation, phosphorylation, methylation, etc are involved in epigenetic regulation of gene activity, by altering the accessibility of the DNA to the transcription machinery.

 
Human Genome Project an international scientific research project with a primary goal of determining the sequence of chemical base pairs which make the DNA and to identify the complete set of genes codified by it. The first draft of the human genome sequence was released on 2001 but new improved versions are available each year.

 
Methylation  of the DNA Chemical modification of DNA by the addition of a methyl (-CH3) group to the cytosine (C) nucleotide, which can be inherited without changing the DNA sequence (epigenetic modification). This modification can be used as an epigenetic mechanism to silence the transcription of a gene.

 
Molecular Biology The study of the structure, function, and makeup of biologically important molecules.

 
Mutation  Any change in the DNA sequence; usually refers to a rare and harmful change in the DNA sequence that is present in less than 1% of the population.

 
Non-coding RNAs Around 97% of the human genome does not code for proteins but recent research is showing that these regions can be transcribed into non-coding RNAs. It is not completely understood if all are functional, but several lines of evidence indicate that the majority have specific fucntions, especially in epigenetic regulation. 

 
Phenotype The observable traits of an organism. The phenotype results from the combination of genetic, epigenetic and environmental factors. 

 
Polymorphism Variation in a region of DNA sequence among different individuals; the variation should be present in at least 1-2% or more in a population to be considered a polymorphism. 

 
Point mutation  Genetic mutation that causes the substitution of a single nucleotide with another. When it occurs inside a protein-coding gene, the change may be classified as:

    Silent - codes for the same amino acid
    Missense - codes for a different amino acid
    Nonsense - codes for STOP codon which may truncate the protein
 

Transcription The process in which a molecule of RNA is synthesised, using as a template the DNA sequence of a gene. The RNA is processed into messenger RNA, which can be translated to generate a functional product. 

If you have any queries and/or suggestions for our glossary send your comments to fcosta@genomicenterprise.com