Introduction

Huntington’s is a rare, hereditary disease that results in psychological disorder, cognitive impairment and worsening motor control¹

Genetics Terminology of HD

Biologically, it arises from the expansion of a repetitive sequence of cytosine-adenosine-guanine (CAG) nucleotides within the coding region of HD gene situated on chromosome 4. The HD gene then synthesizes protein Huntington (HTT) which is located within many tissues throughout the body, including the central nervous system (CNS). However, its function remains incompletely clarified, it is believed that it plays a vital function in cellular events such as protein trafficking, transport of vesicles and selective autophagy. When the CAG exceeds the typical range of 6 to 26 repetitions, it becomes unstable and may further expand to successive offspring. Furthermore, HD can manifest at any point in an individual’s lifespan, although it typically emerges during middle adulthood in the majority of cases.¹

Signs and Symptoms

• Seizures
• Depression
• Memory loss
• Mood swings
• Hallucinations
• Difficulty in speech
• Chorea (Involuntary Movements)²

Treatment

No such cure has been developed yet to eliminate HD from an individual’s life but since the introduction of recent advancements in gene therapy, including antisense oligonucleotides, small interfering RNAs and gene editing have brought hope to Huntington’s community.⁴

In the absence of a cure, genetic interventions as well as tetrabenazine (TBZ) drug (used to treat chorea) remain the foundation of Huntington’s treatment.⁵