What is Huntington's Disease?
Huntington’s Disease is a fatal, neurodegenerative disorder that causes neuronal death. This is a rare genetic disorder, and symptoms typically appear in adulthood (30 - 40 years old) (John Hopkins Medicine, 2020). There are two forms: adult-onset and early-onset Huntington’s disease. Symptoms include cognitive decline, involuntary movements, memory loss, etc. Basal ganglia of the brain is targeted in this disease, and its normal function is to refine motor control (Ross & Tabrizi, 2011).
Genetic Influence
Huntington’s Disease is an autosomal dominant disorder, linked to a single gene mutation in HTT. HTT gene produces harmful forms of the huntingtin protein (Rook & Southwell, 2022). Toxic buildup of this protein causes neuronal dysfunction and cell death. CAG repeats are the main cause of the disease, and will affect the severity of symptoms (John Hopkins Medicine, 2020). The number of repeats is important for determining whether or not an individual has the mutation. 40 or more CAG repeats will always result in onset of the disease (Ross & Tabrizi, 2011).
Treatments
CONTROL BODY MOVEMENTS - Tetrabenazine - Valbenazine - Deutetrabenazine MOOD STABILIZERS - Divalproex - Lamotrigine ANTIPSYCHOTICS - Olanzapine - Aripiprazole (MAYO Clinic, 2023)
Innovative Research
CRISPR-based editing is being researched as a treatment option in hopes of creating proper gene regulation and silencing harmful mutations (Shin & Lee, 2017). CRISPR/Cas9 studies have shown that expression level of HTT could be controlled by targeting certain non-coding regions of the HTT gene (Shin & Lee, 2017). Neuronal damage can be significantly reduced with the use of Antisense oligonucleotides. These strands bind to HTT and block translation, preventing harmful protein buildup (Rook & Southwell, 2022).