Many autoimmune diseases including Alzheimer's disease, ALS, multiple sclerosis, and others have genetic underpinnings. What if scientists could figure out which genetic factors are responsible for their illness? 

Neurogenetics is a new field of scientific research that uses recent advances in genome sequencing in order to better understand the cause of brain and nerve disorders. The Yale Medicine Neurogenetics Program offers whole exome sequencing, an affordable and efficient technique of pinpointing genetic factors of inherited disease. That can help patients determine the extent to which their genetic material plays a role in their condition.

Neurogenetics is also helping to advance the concept of personalized clinical care. With a comprehensive understanding of a patient’s genetic profile and medical history, physicians can create highly tailored treatment programs for each patient. For example, a cancer patient can now receive genome analysis of the specific mutations within a tumor. Based on those results, doctors can then assess whether cancer medications (which can be highly toxic) will even work before administering the drug.

The Human Genome Project—a global effort to map each gene in the human body—represented a major breakthrough when it was completed in 2003. Then scientists developed whole exome sequencing, which looks just at the small portion of DNA that is usually responsible for genetic diseases, which made the tool more affordable and practical.

Today, researchers can study the DNA of hundreds of patients with a given condition to search for patterns that may exist in their genomes. Thanks to those and other advancements, the field of neurogenetics has already successfully identified genes related to the development of Alzheimer’s, Parkinson’s, Huntington’s, and Multiple Sclerosis.

Not every neurological diagnosis is straightforward. For example, some patients might exhibit the characteristic tremors and motor control issues of Parkinson’s disease, but they also might have other symptoms, such as memory problems, which are not common in Parkinson's patients.

In these difficult-to-diagnose cases, patients are often referred to Yale Medicine, where they receive a more precise diagnosis.

Physicians at the Neurogenetics Program treat adult and pediatric patients. Among adults, most of the patients treated have some kind of neurodegenerative disease or genetic form of epilepsy. Among children, the most commonly treated patients have some kind of mental development delay or autism spectrum disorder.

Yale Medicine’s Center of Genomic Analysis is part of a select group called the Consortium for Mendelian Genomics, which is at the forefront of next-generation genetic sequencing work. Patients treated there will benefit from very sophisticated tools and analysis.

For example, some patients—adults and children—have disease related to their mitochondria, the tiny structures inside cells that function as “energy factories” for the body. Mitochondria have their own DNA, which is completely distinct from the famous “double helix” DNA that makes up each person’s chromosomes.

The brain and nervous system require a lot of energy, so any abnormalities in the mitochondria could lead to brain and muscle diseases. Physicians can screen for mitochondrial defects and traditional genetic mutations.

In addition, if genetic abnormalities are not immediately obvious, your doctor can conduct genetic sequencing of family members. For example, by analyzing the genetic profile of a child with autism and both of his parents, physicians can hunt for patterns that might contribute to the disorder.

This information might help young parents decide if they want to have another child. Alternatively, clinicians may be able to refer patients to an appropriate clinical trial, where they can access new treatments that have not yet been approved for the general patient population.

Patients treated will have access to experimental new treatments that might benefit their condition. “My duty is not only to offer the most comprehensive evaluation of the most difficult to treat patients, but also to connect these patients to the latest clinical trials and treatment modalities,” says neurologist Anna Szekely, MD. Patients can also volunteer their genetic information for scientific research. Collectively, hundreds of genetic profiles help scientists cross-compare abnormalities and contribute to advancements in drug and treatment research. 

Personalized medicine is the idea that each person’s treatment should be specifically tailored to his or her medical history and genetic profile.

Now, as researchers continue to search for breakthrough cures for most neurological conditions, genomic sequencing can help physicians choose the best drugs or therapies to address symptoms, and customize a treatment plan based on forecasts about disease progression.