No, Huntington's Disease (HD) and Autism Spectrum Disorder (ASD) are fundamentally different—HD is a rare, inherited neurodegenerative disorder causing brain cell death, while ASD is a common neurodevelopmental condition affecting brain wiring from early life, but they share some overlapping behavioral symptoms (like social withdrawal, irritability, repetitive behaviors) and underlying immune-related genetic pathways, especially in juvenile HD, leading to potential misdiagnosis.
ASD primarily affects early childhood and is associated with genetic mutations impacting brain development, while HD, an autosomal dominant disorder, leads to progressive neurodegeneration due to mutations in the HTT gene. Despite their differences, both disorders share common genetic pathways and molecular mechanisms.
The disease attacks areas of the brain that help to control voluntary (intentional) movement, as well as other areas. People living with HD develop uncontrollable dance-like movements (chorea) and abnormal body postures, as well as problems with behavior, emotion, thinking, and personality.
In our clinical experience at a Huntington's disease specialty clinic, we have consistently noted adverse patient reports of symptoms such as urinary frequency, urgency, incontinence (both urinary and fecal), constipation, chronic diarrhea, and sexual dysfunction among individuals with HD, often in combination.
Of all the psychiatric manifestations of HD, the executive dysfunction syndrome of HD, while difficult to define and characterize, may be the most common. Individuals with this syndrome may become apathetic, irritable, disinhibited, impulsive, obsessional, and perseverative.
Huntington's disease often causes trouble with cognitive skills. These symptoms may include: Trouble organizing, prioritizing or focusing on tasks. Lack of flexibility or getting stuck on a thought, behavior or action, known as perseveration.
The neuropsychiatric symptoms of Huntington's disease often mimics those of bipolar disorder, leading to frequent misdiagnosis. A comprehensive clinical evaluation that includes genetic testing, neuroimaging, and consideration of both neuropsychiatric and motor symptoms is crucial for accurate diagnosis.
HD affects the whole brain, but certain areas are more vulnerable than others. Pictured above in blue is the striatum – an area deep in the brain that plays a key role in movement, mood, and behavior control. The striatum is the part of the brain that is most affected by HD.
It is important to remember that these outbursts of anger are commonly the result of the brain changes in HD, and the person with HD may not understand that you are trying to help them. These brain changes can make it difficult or impossible for someone with HD to view situations from the perspectives of others.
Clinical characteristics included wide-based station, lateral swaying, spontaneous knee flexion, variable cadence, and parkinsonian features. Biomechanical analysis illustrated that gait characteristics varied in each walk, with a mean decrease in velocity, stride length, and cadence.
Speech changes are typically mild initially but can get worse over time. Speech can become slurred (if muscles in the face and tongue become weak) or lose its natural rhythm and sound 'jerky' (if you have difficulty coordinating your breathing with speech).
Another meta-analysis reported that the average pain prevalence in HD was about 41%, ranging from 36 to 46% (Sprenger et al., 2019).
Medicines to control movement include tetrabenazine (Xenazine), deutetrabenazine (Austedo) and valbenazine (Ingrezza). They have been approved by the Food and Drug Administration to suppress involuntary jerking and writhing movements, known as chorea. Chorea can happen as a result of Huntington's disease.
Around 90% of autism cases are attributed to genetic factors, meaning autism is highly heritable, with many different genes contributing, rather than a single cause, often interacting with environmental influences during early brain development, though specific environmental factors don't cause it but can increase risk. Twin studies show strong genetic links, with concordance rates between 60-90% in identical twins, and research points to complex interactions of many genes and prenatal/perinatal factors.
The "6-second rule" for autism is a communication strategy where a speaker pauses for about six seconds after asking a question or giving information, giving the autistic person extra time to process it without feeling rushed, which helps reduce anxiety and allows for a more thoughtful response, reducing frustration for both parties. Instead of repeating or rephrasing, which can be confusing, you wait, and if needed, repeat the exact same words after the pause.
memory problems. low mood, depression and anxiety. changes in your behaviour and personality, such as becoming more irritable or impulsive – sometimes other people find these changes easier to notice. small twitching or jerking movements that you cannot control (called chorea)
Intermittent explosive disorder involves repeated, sudden bouts of impulsive, aggressive, violent behavior or angry verbal outbursts. The reactions are too extreme for the situation. Road rage, domestic abuse, throwing or breaking objects, or other temper tantrums may be symptoms of intermittent explosive disorder.
Overview of HD's Behavioral and Psychiatric Symptoms
People with HD may suffer from depression and other conditions found in the general population, such as mania, obsessive compulsive disorder, or various forms of psychosis.
And for social and cultural as well as medical and scientific reasons, it played a far more important role in defining the discrete clinical entity that soon came to be known as 'Huntington's chorea' and by the late 1960s, as 'Huntington's disease'.
At this stage, a person with Huntington's is no longer able to do their own personal care and domestic responsibilities, and will have difficulty with mobility, needing to be in a chair or bed most of the time. Swallowing may be difficult and there may be significant weight loss.
Early Signs of Huntington's Disease
In patients with Huntington's disease, neurons in a part of the brain called the striatum are among the hardest-hit. Degeneration of these neurons contributes to patients' loss of motor control, which is one of the major hallmarks of the disease.
There are two main types of Huntington's disease: Adult-onset: This is the most common type. Symptoms usually start after age 30. Early-onset (juvenile Huntington's disease): This rare type affects children and teenagers.
Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS) are both relentlessly progressive neurodegenerative disorders for which diagnostic and predictive gene testing have been available for ~20years. HD is a single gene autosomal dominant disorder whereas ALS is highly heterogeneous and complex.
Huntington's disease is an inherited genetic condition that causes dementia. It causes a slow, progressive decline in a person's movement, memory, thinking and emotional state.