PRICKLE1-related progressive myoclonus epilepsy with ataxia

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

PRICKLE1-related progressive myoclonus epilepsy with ataxia is a rare inherited condition characterized by recurrent seizures (epilepsy) and problems with movement. The signs and symptoms of this disorder usually begin between the ages of 5 and 10.

Problems with balance and coordination (ataxia) are usually the first symptoms of PRICKLE1-related progressive myoclonus epilepsy with ataxia. Affected children often have trouble walking. Their gait is unbalanced and wide-based, and they may fall frequently. Later, children with this condition develop episodes of involuntary muscle jerking or twitching (myoclonus), which cause additional problems with movement. Myoclonus can also affect muscles in the face, leading to difficulty swallowing and slurred speech (dysarthria).

Beginning later in childhood, some affected individuals develop tonic-clonic or grand mal seizures. These seizures involve a loss of consciousness, muscle rigidity, and convulsions. They often occur at night (nocturnally) while the person is sleeping.

PRICKLE1-related progressive myoclonus epilepsy with ataxia does not seem to affect intellectual ability. Although a few affected individuals have died in childhood, many have lived into adulthood.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

PRICKLE1-related progressive myoclonus epilepsy with ataxia is caused by mutations in the PRICKLE1 gene. This gene provides instructions for making a protein called prickle homolog 1, whose function is unknown. Studies suggest that it interacts with other proteins that are critical for brain development and function.

Mutations in the PRICKLE1 gene alter the structure of prickle homolog 1 and disrupt its ability to interact with other proteins. However, it is unclear how these changes lead to movement problems, seizures, and the other features of PRICKLE1-related progressive myoclonus epilepsy with ataxia.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

Some cases of PRICKLE1-related progressive myoclonus epilepsy with ataxia are inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Other cases of PRICKLE1-related progressive myoclonus epilepsy with ataxia are considered autosomal dominant because one copy of the altered gene in each cell is sufficient to cause the disorder. These cases result from new mutations in the gene and occur in people with no history of the disorder in their family.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

The prevalence of PRICKLE1-related progressive myoclonus epilepsy with ataxia is unknown. The condition has been reported in three large families from Jordan and northern Israel and in at least two unrelated individuals.

Understanding terms used in the source

These definitions explain medical words used above. A definition is not evidence that another condition is present, and it does not predict how a symptom will develop. Ask the clinician which terms apply to the actual examination or test result.

Loss of consciousness

Loss of awareness of oneself or one's surroundings, involving (i) a loss of normal motor control is evident as flaccidity or stiffness, either of which can be accompanied by jerking movements, and postural control is lost so that patients fall if they are in an upright position; (ii) normal responsiveness is lost; and (iii) the patient experiences amnesia for the event. Loss of consciousness my be transitory (e.g., syncope) or prolonged.

Progressive

Applies to a disease manifestation that increases in scope or severity over the course of time, i.e., that worsens with age.

Dysarthria

Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed.

Myoclonus

Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements.

Recurrent

Applies to a sign, symptom or manifestation that occurs multiple times separated by intervals in which the sign, symptom, or manifestation is not present.

Which doctor should you see?

The suggested department for discussing PRICKLE1-related progressive myoclonus epilepsy with ataxia is Neurology, with a neurologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which nervous-system findings help explain the symptoms?
• Would an assessment of walking, communication or daily function be helpful?
• Are rehabilitation or other specialist services relevant?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for PRICKLE1-related progressive myoclonus epilepsy with ataxia. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.