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A cell that fuses with another cell during conception in organisms that reproduce sexually. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female gamete is called an ovum (or egg), and a male gamete is called a sperm.


EU General Data Protection Regulation (GDPR) replaces the Data Protection Directive 95/46/EC and was designed to harmonise data privacy laws across Europe, to protect and empower all EU citizens data privacy, and to reshape the way organisations across the region approach data privacy. The final Regulation provides more rights to citizens to be better informed about the use made of their personal data, and gives clearer responsibilities to people and entities using personal data.
GDPR covers patients™ fundamental right to protection of their health data and is an important issue in diverse contexts such as healthcare, including care given through eHealth or in a cross-border healthcare context, and research (clinical trials, clinical investigations, epidemiological research, patient registries, etc). Health and genetic data belong to the category of sensitive data™, and benefit from additional protection.

Refer to Regulation (EU) 2016/679 for more information.

Gene Mutation

A gene mutation is a permanent alteration in the DNA sequence that makes up a gene. Mutations range in size, affecting from a single DNA building block (base pair) to a large segment of a chromosome with multiple genes. Gene mutations can be classified in two ways:

  1. Germ-line mutations are inherited from a parent and are present throughout a person's life in every cell in the body. These mutations are present in the parent's egg or sperm cells, and are transmitted as hereditary mutations.
  2. Somatic mutations occur at some point during a person's life only in certain cells, not in every cell in the body. These changes can be caused by environmental factors such as ultraviolet radiation from the sun, or can occur if a mistake is made as DNA copies itself during cell division. These acquired mutations cannot be passed on to the next generation.

Gene Therapy

Gene therapy is an experimental technique that replaces a faulty gene in a cell, or adds a new gene to cure or prevent disease. In the future, this technique may allow doctors to treat a disorder instead of using medicines or surgery. Researchers are testing several approaches to gene therapy, including replacing a mutated gene that causes disease, deactivating a mutated gene that is not properly functioning, or introducing a new gene into the body to help fight a disease.

Although gene therapy is a promising treatment option for a number of diseases, the technique is still under study to make sure that it will be safe and effective. Gene therapy is currently only being tested for the treatment of diseases that have no other cures.

Gene Therapy Advisory Committee

Gene Therapy Advisory Committee

Generic Medicine

A generic medicine is a medicine that is developed to be the same as a medicine that has already been authorised, called the 'reference medicine'.

A generic medicine contains the same active substances as the reference medicine, and it is used at the same doses to treat the same diseases. However, a generic medicine's inactive ingredients, name, appearance, and packaging can be different from the reference medicine's.

Generic medicines are manufactured according to the same quality standards as all other medicines.

A company can only develop a generic medicine for marketing once the period of exclusivity on the reference medicine has expired. This is usually 10 years from the date of first authorisation.

Each medicine has an approved name called the generic name. A group of medicines that have similar actions often have similar-sounding generic names. For example, phenoxymethylpenicillin, ampicillin, amoxicillin, and flucloxacillin are in the same group of antibiotics.

Genetically Modified Organism

A genetically modified organism (GMO) is an organism whose genetic material has been altered in the laboratory. Genetic modifications are made to produce certain traits (such as disease resistance in crops) or to cause the organism to produce specific biological products (for example, bacteria have been altered in order to produce insulin for diabetes treatment, and plants have been altered to make antibodies and blood-clotting factors).

GMOs are used in the production of medicines, and in new forms of medicines such as gene therapy.

Genetic modification is also a useful tool for scientists in many areas of research, including those who study the mechanisms of human and other diseases.


The genome is an organism™s complete set of genetic instructions. Each genome contains all of the information needed to build that organism and allow it to grow and develop. The genome includes both the genes and the non-coding sequences of the DNA/RNA. The human genome contains about 35,000 genes.

The Human Genome Project, completed in 2003, was an international effort to identify all the genes in human DNA, and to determine the sequences of the 3 billion base pairs of DNA. It took 13 years.

Genome research has helped diagnose diseases and find genetic markers for certain diseases.

Genome-wide association study

In genetics, a genome-wide association study is an observational study of a genome-wide set of genetic variants in different individuals to see if any variant is associated with a trait.

Genome-wide inferred study

In genetics, a genome-wide inferred study is an observational study of a genome-wide set of genetic variants in different individuals to see if any variant is inferred from a trait.

Genomic Marker

A genomic marker (or genetic marker) is a specific gene or DNA sequence that is associated with a known characteristic. They are used to study the relationship between diseases and genetics. A genetic marker can serve as a flag for another gene. It must be on the same chromosome and near enough to the other gene that the two genes are genetically linked and are usually inherited together.

Genomic technologies

Genomic technologies are those new methods, technologies, and instruments used to study and manipulate the genome.


Genomics is the branch of biology that studies the entire genome of an organism by sequencing, assembling, and analysing the function and structure of its DNA. Advances in genomics have allowed great progress to be made in understanding diverse illnesses.

Genomics research can develop more effective therapeutic strategies, and better decision-making tools for patients and healthcare providers.

Genotoxicity Study

A genotoxicity study is designed to detect compounds that cause genetic damage either directly or indirectly in cells exposed to the toxic substrates. Genotoxicity studies may be performed in vitro or in vivo.

Compounds which are positive in tests that detect such damage have the potential to cause cancer and/or heritable defects. No single test is capable of detecting all relevant genotoxic agents therefore, the usual approach is to carry out a battery of tests that are complementary rather than representing different levels of hierarchy.

A standard study battery has the following tests:

  1. A test for gene mutation in bacteria,
  2. An in vitro test with cytogenetic (concerned with the study of the structure and function of the cell) evaluation of chromosomal damage with mammalian cells,
  3. An in vivo test for chromosomal damage using rodent haematopoietic (blood or blood cell forming) cells.


A chemical or other agent that provokes a harmful change in a person™s genetic material regardless of the mechanism by which the change is induced. A genotoxin can cause mutations in DNA (a mutagen), it can trigger cancer (a carcinogen), or it can cause a birth defect (a teratogen).


The genotype is an individual's collection of genes, including which genetic variants they have. It is the entire complex of genes inherited from both parents. The genotype determines the hereditary characteristics of an individual. A genotype can be determined by sequencing an individual™s genome.


Genotyping is the process of determining differences in the genetic make-up or genotype of an individual by examining their individual DNA sequence. This can be done by comparing one person's genotype to another individual's sequence, or against a reference sequence.

Gold Standard

In medicines development, the gold standard often refers to the best available therapy/product/treatment. Depending on the context, the gold standard may also mean different things. In clinical design, a double-blind, randomised

trial is seen by many as the gold standard.

The gold standard may change over time as new methods/treatments/medicines become available. For example, the gold standard test for the diagnosis of aortic dissection (a tear inside the aorta) used to be the aortogram, which had a sensitivity as low as 83% and a specificity as low as 87%. Now, the magnetic resonance angiogram (MRA) is seen by many as the new gold standard test for aortic dissection, with a sensitivity and a specificity both over 90%.

Good Clinical Practice

Good Clinical Practice (GCP) is an international ethical and scientific quality standard for designing, conducting, recording and reporting clinical trials that involve human participants. The International Conference on Harmonisation (ICH) has issued a guideline with the objective to provide a unified standard to facilitate the mutual acceptance of clinical data by the regulatory authorities in the jurisdictions pertaining to the ICH.

Good Distribution Practice

Good Distribution Practice (GDP) is a standard ensuring that the quality of a medicine is maintained throughout the distribution network, so that authorised medicines are distributed to retail pharmacists and others selling medicines to the general public without any alteration of their properties.

Good Laboratory Practice

Good Laboratory Practice (GLP) is a standard by which laboratory studies are designed, implemented and reported so that there is public assurance that the results are correct and that the experiment can be reproduced exactly at any time in the future.

Good Manufacturing Practice

The purpose of Good Manufacturing Practice (GMP) is to ensure that products are consistently produced according to the appropriate quality standards.

The reliability of the quality of products is guaranteed by controlling the five critical parameters: manpower, environment, equipment, methods, materials.

Good Pharmacovigilance Practices

Good Pharmacovigilance Practice (GVP) is a quality standard for monitoring the safety of medicines and if necessary, taking action to reduce the risks and increase the benefits of medicines. It ensures the detection, collection, assessment, understanding, and prevention of adverse effects with medicinal products.

Group sequential design

Group sequential design is an example of a statistical approach in clinical trial design. It means that the sample size of the trial is not fixed in advance, and data is sequentially evaluated as it is collected. This is known as interim analysis, and might be carried out at several points in time. The trial can be stopped when significant results are seen, or if the interim analysis shows that there are safety concerns, or that the trial will not in fact be able to give a significant result. In this case no more recruitment of patients or further sampling from the patients involved will occur.

Before the trial starts, the 'stopping rule' (i.e. the reason for stopping) must be documented and explained. The stopping rule is a description of exactly what the interim analysis must show to cause the trial to be stopped.

Group sequential analysis can lead to a conclusion much earlier than would be possible with a classical design. It can therefore save time and resources, and reduces the exposure of patients to inferior treatments.

Guarantee-time bias

If a group of trial participants receiving a placebo are monitored/followed up from the moment they enrol in a trial, but the treatment for another group of trial participants does not begin straight away, this time lag can cause bias in the trial.  This particular type of bias is called 'guarantee-time bias'.

Guarantee-time bias means that the participants in the treatment arm will only be monitored/followed up if they survive (or, for example, do not have symptoms that the treatment aims to prevent) for the whole of the time lag. Any that do not will be excluded from the trial, and this means the treatment arm is selected on a different basis to the placebo arm.

The easiest way to avoid guarantee-time bias is to use matching. Participants in the treatment arm and the placebo arm are individually matched. If a participant in the treatment arm has to wait 30 days to begin the trial, they are matched with a placebo participant who has also survived or survived without symptoms for 30 days since enrolment. This is also known as establishing matched pairs.

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