Genetics is the study of heredity and specifically single genes in isolation and their effects on an organism.
Genomics is a more recent term describing the study of all the genes in an individual (genome), including interactions with environmental factors and even interactions with other genes. Common complex conditions such as asthma, diabetes, heart disease are caused by gene-environment interactions.
The study of genomics is discovering new possibilities for new diagnostics techniques, therapies and treatments for some of these complex diseases.
A genome is all of a living organism’s genetic material, which includes the entire set of hereditary instructions for building, running and maintaining the organism.
Patterns of Inheritance
A pattern of inheritance describes the pathway in which a given genetic trait or genetic condition is passed down to the next generation.
A gene mutation is a permanent change in the DNA sequence that makes up a gene.
Gene mutations can be inherited from a parent or acquired during a person’s lifespan.
Hereditary mutations are mutations passed on from parent to child.
Acquired mutations occur in the DNA of individual cells at some time during a person’s lifespan. These types of mutations can be caused by environmental factors or during cell division. Acquired mutations cannot be passed on from a parent to a child.
Modes of Inheritance
Autosomal Dominant Inheritance
Autosomal dominant condition describes a condition that is expressed in an individual who has one damaged copy of the gene. These conditions are caused by genes that are located on chromosomes other than the sex chromosomes (X and Y).
Autosomal Recessive Inheritance
An autosomal recessive condition describes a condition that is expressed in an individual who have two damaged copies of the same gene or one damaged copy from each parent. Autosomal recessive conditions occur when genes that are located on chromosomes other than the sex chromosomes, X and Y are damaged.
Mitochondrial (Maternal) Inheritance
Mitochondrial inheritance describes a condition which is expressed in individuals with mutations in mitochondrial DNA (mtDNA). All mitochondria descend from a small number of mitochondria in the mother's egg at conception. Male sperm typically do not contribute mitochondria.