Genetics is the study of how, in all living things, the characteristics and qualities of parents are given to their children by their genes. In the last 50 years, researchers have learned each of us has more than 20,000 genes and have identified many genetic mutations (sometimes called genetic variants) in them that are responsible for diseases. This led to the development of thousands of tests that – often using just a bit of blood or saliva – can determine if you are at risk for certain diseases or conditions.
Medical Definition of Genetics is the scientific study of heredity. Genetics pertains to humans and all other organisms. So, for example, there is human genetics, mouse genetics, fruit fly genetics, etc.
Human genetics today comprises a number of overlapping fields, including:
- Classical or Formal Genetics -- the study of the transmission of single genes within families and the analysis of more complex types of inheritance.
- Clinical genetics -- the diagnosis, prognosis and, in some cases, the treatment of genetic diseases.
- Genetic counseling -- an important area within clinical genetics involving the diagnosis, risk assessment, and interpersonal communication.
- Cancer genetics -- the study of genetic factors in inherited and sporadic cancer.
- Cytogenetics -- the study of chromosomes in health and disease.
- Biochemical Genetics -- the biochemistry of nucleic acids and proteins including enzymes.
- Pharmacogenetics -- how genes govern the absorption, metabolism and disposal of drugs and untoward reactions to them.
- Molecular Genetics -- the molecular study of genetics including particularly DNA and RNA.
- Immunogenetics -- the genetics of the immune system including blood groups, HLA, and the immunoglobulins.
- Behavioral Genetics -- the study of genetic factors in behavior in health and disease including mental retardation and mental illness.
- Population Genetics -- the study of genes within populations including gene frequencies, the gene pool, and evolution.
- Reproductive Genetics -- the genetics of reproduction including genes and chromosomes in germ cells and the early embryo.
- Developmental Genetics -- the genetics of normal and abnormal development including congenital malformations (birth defects). (Cancer genetics- The study of the genetic factors in inherited and sporadic cancer)
- Ecogenetics -- the interaction of genetics with the environment.
- Forensic Genetics -- the application of genetic knowledge, including DNA, to legal matters.