X-linked dystonia-parkinsonism

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

X-linked dystonia-parkinsonism is a movement disorder that has been found only in people of Filipino descent. This condition affects men much more often than women.

Parkinsonism is usually the first sign of X-linked dystonia-parkinsonism. Parkinsonism is a group of movement abnormalities including tremors, unusually slow movement (bradykinesia), rigidity, an inability to hold the body upright and balanced (postural instability), and a shuffling gait that can cause recurrent falls.

Later in life, many affected individuals also develop a pattern of involuntary, sustained muscle contractions known as dystonia. The dystonia associated with X-linked dystonia-parkinsonism typically starts in one area, most often the eyes, jaw, or neck, and later spreads to other parts of the body. The continuous muscle cramping and spasms can be disabling. Depending on which muscles are affected, widespread (generalized) dystonia can cause difficulty with speaking, swallowing, coordination, and walking.

The signs and symptoms of X-linked dystonia-parkinsonism vary widely. In the mildest cases, affected individuals have slowly progressive parkinsonism with little or no dystonia. More severe cases involve dystonia that rapidly becomes generalized. These individuals become dependent on others for care within a few years after signs and symptoms appear, and they may die prematurely from breathing difficulties, infections (such as aspiration pneumonia), or other complications.

ORPHANET DEFINITION X-linked dystonia-parkinsonism (XDP) is a neurodegenerative movement disorder characterized by adult-onset parkinsonism that is frequently accompanied by focal dystonia, which becomes generalized over time, and that has a highly variable clinical course.

Inheritance

From: MedlinePlus Genetics, National Library of Medicine

X-linked recessive

Frequency in the source

From: MedlinePlus Genetics, National Library of Medicine

Point prevalence: <1 / 1 000 000; Europe; Class only. Point prevalence: 1-9 / 1 000 000; Philippines; Value and class.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Blepharospasm · Frequent (79-30%)

A focal dystonia that affects the muscles of the eyelids and brow, associated with involuntary recurrent spasm of both eyelids.

Bradykinesia · Frequent (79-30%)

Bradykinesia literally means slow movement, and is used clinically to denote a slowness in the execution of movement (in contrast to hypokinesia, which is used to refer to slowness in the initiation of movement).

Chorea · Frequent (79-30%)

Chorea (Greek for 'dance') refers to widespread arrhythmic involuntary movements of a forcible, jerky and restless fashion. It is a random-appearing sequence of one or more discrete involuntary movements or movement fragments. Movements appear random because of variability in timing, duration or location. Each movement may have a distinct start and end. However, movements may be strung together and thus may appear to flow randomly from one muscle group to another. Chorea can involve the trunk, neck, face, tongue, and extremities.

Focal dystonia · Frequent (79-30%)

A type of dystonia that is localized to a specific part of the body.

Hand tremor · Frequent (79-30%)

An unintentional, oscillating to-and-fro muscle movement affecting the hand.

Myoclonus · Frequent (79-30%)

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

Parkinsonism with favorable response to dopaminergic medication · Frequent (79-30%)

Parkinsonism is a clinical syndrome that is a feature of a number of different diseases, including Parkinson disease itself, other neurodegenerative diseases such as progressive supranuclear palsy, and as a side-effect of some neuroleptic medications. Some but not all individuals with Parkinsonism show responsiveness to dopaminergic medication defined as a substantial reduction of amelioration of the component signs of Parkinsonism (including mainly tremor, bradykinesia, rigidity, and postural instability) upon administration of dopaminergic medication.

Postural instability · Frequent (79-30%)

A tendency to fall or the inability to keep oneself from falling; imbalance. The retropulsion test is widely regarded as the gold standard to evaluate postural instability, Use of the retropulsion test includes a rapid balance perturbation in the backward direction, and the number of balance correcting steps (or total absence thereof) is used to rate the degree of postural instability. Healthy subjects correct such perturbations with either one or two large steps, or without taking any steps, hinging rapidly at the hips while swinging the arms forward as a counterweight. In patients with balance impairment, balance correcting steps are often too small, forcing patients to take more than two steps. Taking three or more steps is generally considered to be abnormal, and taking more than five steps is regarded as being clearly abnormal. Markedly affected patients continue to step backward without ever regaining their balance and must be caught by the examiner (this would be called true retropulsion). Even more severely affected patients fail to correct entirely, and fall backward like a pushed toy soldier, without taking any corrective steps.

Progressive extrapyramidal muscular rigidity · Frequent (79-30%)

A progressive degree of muscular rigidity (continuous contraction of muscles with constant resistance to passive movement).

Resting tremor · Frequent (79-30%)

A resting tremor occurs when muscles are at rest and becomes less noticeable or disappears when the affected muscles are moved. Resting tremors are often slow and coarse.

Shuffling gait · Frequent (79-30%)

A type of gait (walking) characterized by by dragging one's feet along or without lifting the feet fully from the ground.

Torsion dystonia · Frequent (79-30%)

Sustained involuntary muscle contractions that produce twisting and repetitive movements of the body.

Aspiration pneumonia · Occasional (29-5%)

Pneumonia due to the aspiration (breathing in) of food, liquid, or gastric contents into the upper respiratory tract.

Gait disturbance · Occasional (29-5%)

The term gait disturbance can refer to any disruption of the ability to walk.

Other findings in the same source

From: Orphanet

Additional reported features include Impaired oropharyngeal swallow response (Occasional (29-5%)); Laryngeal stridor (Occasional (29-5%)); Limb dystonia (Occasional (29-5%)); Protruding tongue (Occasional (29-5%)); Frequent falls (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: MedlinePlus Genetics, National Library of Medicine

Adult

Inheritance in the source

From: MedlinePlus Genetics, National Library of Medicine

X-linked recessive

Frequency and the population described

From: MedlinePlus Genetics, National Library of Medicine

Point prevalence: <1 / 1 000 000; Europe; Class only. Point prevalence: 1-9 / 1 000 000; Philippines; Value and class.

Understanding the inheritance label

From: MedlinePlus Genetics

An X-linked recessive pattern involves a gene on the X chromosome. The number of X chromosomes and the particular genetic change influence how a condition is expressed. A genetic counsellor should interpret the result and the family history before discussing risks for relatives or future pregnancies.

Which doctor should you see?

The suggested department for discussing X-linked dystonia-parkinsonism 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 X-linked dystonia-parkinsonism. 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.