Download Genomics Glossary

Genomic Glossary
Allele*
Alternative form of a genetic locus; a single
allele for each locus is inherited from each
parent (e.g., at a locus for eye color the
allele might result in blue or brown eyes).
Base Pair (bp)*
Two nitrogenous bases (adenine and
thymine or guanine and cytosine) held
together by weak bonds. Two strands of
DNA are held together in the shape of
a double helix by the bonds between
base pairs.
Bioinformatics*
The science of managing and analyzing
biological data using advanced computing
techniques. Especially important in
analyzing genomic research data.
Candidate Gene*
A gene located in a chromosome region
suspected of being involved in a disease.
Compound Heterozygous
A pattern of autosomal recessive
inheritance in which the child receives two
different pathogenic mutations in the same
gene, typically one from each unaffected
parent; this differs from homozygous
mutations in which the child receives two
copies of an identical pathogenic mutation,
one from each parent.
Epigenome*
Set of chemical compounds that modify,
or mark, the genome in a way that tells
it what to do, where to do it, and when
to do it. The marks, which are not part of
the DNA itself, can be passed on from
cell to cell as cells divide, and from one
generation to the next.
Whole-Exome Sequencing (WES)
Determination of the order of nucleotides
(base sequences) in all of the proteincoding regions of the genome. Compare
to Whole-Genome Sequencing (WGS),
which includes the Exome and all intronic
and intergenic regions.
Exon*
The protein-coding DNA sequence
of a gene.
Gene*
The fundamental physical and functional
unit of heredity. A gene is an ordered
sequence of nucleotides located in
a particular position on a particular
chromosome that encodes a specific
functional product (i.e., a protein or
RNA molecule).
Next-Generation Sequencing
A high-throughput (fast) method of
sequencing that involves randomly
sequenced pieces of the genome, with
no foreknowledge of where the piece
originally came from. This can be
contrasted with “directed” strategies
in which pieces of DNA from known
chromosomal locations are sequenced.
Incidental Finding
Genomic variants that are unexpected
or unrelated to a patient’s symptoms; an
example is the presence of breast cancer
predisposition variant in a child tested
for the purpose of identifying the etiology
of epilepsy.
Indel
Small insertion or deletion of one or
more nucleotides, usually detected
by gene sequencing methods. This is
in comparison to larger (hundreds to
thousands of base pair) insertions and
deletions which are conventionally called
Copy Number Variants (CNVs), usually
detected by microarray methods.
Intron*
DNA sequence that interrupts the proteincoding sequence of a gene; an intron is
transcribed into RNA but is cut out of the
message before it is translated into protein.
Monogenic Disorder
A disorder caused by mutation
of a single gene.
Multiplexing*
A laboratory approach that performs
multiple sets of reactions in parallel
(simultaneously); greatly increasing speed
and throughput.
Nucleotide*
A subunit of DNA or RNA consisting
of a nitrogenous base (adenine, guanine,
thymine, or cytosine in DNA; adenine,
guanine, uracil, or cytosine in RNA),
a phosphate molecule, and a sugar
molecule (deoxyribose in DNA and ribose
in RNA). Thousands of nucleotides are
linked to form a DNA or RNA molecule.
Omics*
Collective term for a range of new highthroughput biological research methods
(e.g., transcriptomics, proteomics, and
metabolomics) that systematically
investigate entire networks of genes,
proteins, and metabolites within cells.
Pharmacogenomics*
The study of the interaction of an
individual’s genetic makeup and response
to a drug.
Single Nucleotide Polymorphism (SNP)*
DNA sequence variations that occur when
a single nucleotide (A, T, C, or G) in the
genome sequence is altered.
* from the Human Genome Project Glossary (http://web.ornl.gov/sci/techresources/Human_Genome/glossary.shtml)
02/14