Genes and Biomarkers: What They Can and Cannot Show

The short answer

A gene record in the Research Library names a stretch of DNA and gives its official symbol and identifiers. A biomarker record names something that can be measured. Neither tells you what to take, what to avoid or what your own genes or lab results mean. They are labels that connect other records, such as studies and compounds, to a measurable biological item.

The library holds about 15,700 gene records and 25 biomarker records, all imported from public databases and ontologies. None has been reviewed by a clinician. Gene and biomarker records are different kinds of things, and this page explains each.

What a gene is

MedlinePlus Genetics describes a gene as the basic physical and functional unit of heredity, made of DNA. [1] Some genes carry instructions for making proteins, and many do not. Scientists keep track of genes by giving them unique names and short symbols. [1]

Official gene symbols

The HUGO Gene Nomenclature Committee (HGNC) names human genes. It gives each named gene a unique symbol, an HGNC ID in the format HGNC:number, and a descriptive name. [2] Symbols use only uppercase letters and numbers, with few exceptions. [2]

This is why symbols are useful for lookup. HGNC states that symbols should not be the same as commonly used abbreviations, to make data retrieval easier. [2] When two records seem to describe the same gene under different names, the HGNC ID is the best thing to compare.

A symbol is also only a name. HGNC notes that genes may be named by structural features, similarity to other genes or even only the presence of an open reading frame, when no function is known. [2] A name therefore does not tell you what the gene does in your body.

What a biomarker is

The FDA and NIH BEST glossary defines a biomarker as a defined characteristic that is measured as an indicator of normal biological processes, pathogenic processes, or responses to an exposure or intervention. [3] A biomarker is not an assessment of how a person feels, functions or survives. [3]

So a biomarker is not a gene, although a gene, a protein or a blood level can each be used as one. The same source lists seven categories, including diagnostic, prognostic, predictive and safety. [3] A biomarker can only be understood in the context of how it is used.

Gene expression is not a treatment effect

Gene expression is the process by which the information in a gene is turned into a function, mostly through making RNA and then proteins. [4] It changes substantially under different conditions and cell types. [4] A study may report that a compound changed the activity of some genes in cells or animals. That is a laboratory observation. It is not evidence that the compound has an effect on a condition in people. See human, animal and laboratory research for what each research model can and cannot show.

Clinical and investigational biomarkers

In regulatory use, a biomarker is qualified for a specific context of use, and it is the biomarker that is qualified, not the measurement method. [3] A biomarker that has not been through that formal process has not been qualified in this sense. The library does not say which biomarkers are qualified, so check the original study for how the measure was used.

No personal genetic recommendations

Genetic testing identifies changes in genes, chromosomes or proteins, and it is voluntary. A geneticist or genetic counselor can explain the pros and cons of a test. [5] The library does not test anyone's genes and offers no personal genetic advice. A gene record linked to a compound is not a reason to start or stop anything. Please talk to a clinician about personal questions.

Reference ranges depend on the lab and the population

A reference range is based on results from large groups of healthy people, and a test may have different ranges for different groups, such as children and adults. [6] Labs often use different methods and so different ranges. [6] A result outside a range may or may not signal a health problem, and lab tests do not give a complete picture of health. [6] For that reason the library does not offer normal values to compare yourself against.

Common misunderstandings

• "A gene linked to a herb means the herb works through that gene." The link may be a database listing or a name match. See relationship types.
• "A gene symbol tells me my risk." It only names a gene.
• "A biomarker is the same as a symptom." The glossary says it is not an assessment of how a person feels or functions. [3]

For terms used across the library, see the glossary, and to browse records go to Genes & Biomarkers.