genomics

Genetics

The study of the general mechanisms of heredity and the variation of inherited traits.

Genomics

A broader field studying the function of all nucleotide sequences within the entire genome of a species, including coding and non-coding regions of DNA.

Gene

The basic unit of heredity, a segment of DNA that contains instructions for producing a specific protein.

Genome

The complete set of genes for a specific species; the human genome contains approximately 20,000 to 25,000 genes.

Proteome

The complete set of proteins a person makes at a given time under certain conditions; the study of this is called proteomics.

DNA

Deoxyribonucleic Acid, the genetic material in a cell containing genes; it is a double-stranded molecule composed of nucleic acids.

Chromosome

A temporary structure, visible during cell division, that is a large chunk of DNA containing many genes.

Nucleus

The part of the cell containing the chromosomes and most of the cell's DNA.

Mitochondrial DNA (mtDNA)

A small amount of DNA found in the mitochondria.

Mitosis

A process of cell division resulting in two identical daughter cells, each having the same number of chromosomes as the parent cell.

Apoptosis

Programmed cell death, a natural process for removing old or damaged cells.

Haploid

A complete set of one of each chromosome (23 chromosomes in humans); gametes (sperm and egg) are haploid.

Diploid

Contains two complete sets of chromosomes, one from each parent (46 chromosomes in humans); somatic cells are diploid.

Allele

An alternative form of a gene at a given locus.

Genotype

An individual's genetic makeup for a specific gene pair or their total genetic makeup.

Phenotype

The observable expression of a specific trait or characteristic (e.g., eye color, blood type).

Homozygous

Having two identical alleles for a particular gene.

Heterozygous

Having two different alleles for a particular gene.

Dominant Trait

A trait expressed when only one copy of the allele is present.

Recessive Trait

A trait expressed only when two copies of the gene are present.

Codominant Expression

When each of two alleles present is expressed equally.

X-linked Inheritance

Traits carried on the X chromosome.

Autosomal Dominant

Traits expressed with at least one dominant allele, appearing in every generation.

Autosomal Recessive

Traits expressed only when both alleles are recessive, potentially skipping generations.

Pleiotropy

When a single gene has effects in more than one tissue or organ.

Mosaicism

The presence of two or more cell populations with different genotypes within a single individual.

Aneuploidy

A change in the number of individual chromosomes or chromosomal segments, leading to an abnormal number of chromosomes.

Trisomy

The addition of a single chromosome (e.g., Down Syndrome - Trisomy 21).

Monosomy

The loss of a single chromosome (e.g., Turner Syndrome, 45,X).

Nullisomy

The loss of a pair of chromosomes.

Maternal Age

Influences the risk of aneuploidy; risk increases significantly with age over 35.

Genetic Variation

Differences in DNA sequences among individuals.

Genetic Susceptibility

Having one or more gene variations that increase an individual's risk for a specific disease.

Genetic Counseling

Providing information and support to individuals and families regarding genetic conditions.

Pharmacogenomics

Studying how genes affect a person's response to drugs.

DNA Profiling/Fingerprinting

Identifying individuals based on unique patterns in their DNA.

DNA Testing Process

Includes quantitation, amplification, and detection of DNA.

Clinical Applications of Genetics

Applications such as bone marrow transplantation, genetic counseling, and pharmacogenomics.