Genetics and neurology are studied together in a branch of science called neurogenetics, which concerns the development and function of the nervous system as well as the role played by genes in its development.
In genetics, the term “phenotype” refers to the physical attributes or characteristics of an organism and the term “genotype” refers to an organism’s genetic makeup. In terms of the nervous system, “phenotype” may refer to the differences in neural characteristics between individuals of the same species, while “genotype” refers to the genetic make-up that determines the different traits expressed by individual organisms.
A wide range of diseases and disorders are determined by neurogenetics and these conditions can have substantial impacts on an individual’s quality of life, behaviour and personality.
As a field, neurogenetics first emerged in the mid-to-late 1900s, following advances made in genetics and molecular biology and inspired by a curiosity about the connection between genes, the brain, behavior and neurological diseases.
It was in the 1960s that Seymour Benzer started to expand the field, becoming thought of by some as the father of neurogenetics. Benzer’s studies of Drosophila (the fruit fly) helped lead to an understanding of the connection between genes and circadian rhythms. He also studied neurodegeneration in fruit flies to try and find ways to suppress diseases of the nervous system.
Many of the conditions that fall under the umbrella of neurogenetics such as Alzheimer’s, Huntington's and epilepsy are still key subjects of research today and much is now understood about the genetic basis of these and many other conditions.
One of the greatest achievements of neurogenetic research is the number of gene loci that have now been linked to specific diseases. For example, APOE ε4, PICALM have been linked to Alzheimer's disease; DR15, DQ6 have been linked to multiple sclerosis; HTT to Huntington's disease and LRRK2, PARK2, PARK7 have been linked to Parkinson's disease.