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Disease Profile

X-linked dystonia-parkinsonism/Lubag

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
<1 / 1 000 000

< 331

US Estimated

< 514

Europe Estimated

Age of onset

Adult

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ICD-10

G24.1

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

DYT3; Dystonia-Parkinsonism, X-linked; XDP;

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
orphanet

Orpha Number: 53351

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.

Epidemiology
Over 500 cases of XDP have been reported in the literature to date, all occurring in the Philippines (Panay Island). The estimated prevalence in the Philippines is 1/322,000 and in the Province of Capiz it is at its highest with a prevalence of 1/4,000 in the male population.

Clinical description
XDP affects mainly males, most female carriers are asymptomatic. The disease typically presents in adulthood (mean: 39 years) with either focal dystonia or, more commonly, parkinsonism. Focal dystonia affects mainly the jaw, neck, eyes and trunk, but also rarely the limbs, pharynx, larynx and tongue, leading to various manifestations such as difficulty with jaw opening and closing, blepharospasm, involuntary tongue protrusion, difficulty swallowing, retrocollis, trunk hyperextension, leg spasms, foot flexion, and foot inversion. Within 2-5 years after onset, 50% of patients have generalized dystonia. Parkinsonism manifests with bradykinesia, rigidity, resting tremor, shuffling gait and postural instability, which may be severe and can lead to walking impairment and frequent stumbling. Less common findings include sensory tricks, myoclonus, chorea and myorhythmia. In those with pure parkinsonism, the disease progresses slowly and is usually non-disabling. Most who develop orobuccolingual and cervical dystonia suffer from lethal complications such as infections, aspiration pneumonia and laryngeal stridor, leading to premature death. Mean duration of illness is 13-16 years.

Etiology
XDP is due to mutations in the TAF1 gene (Xq13.1) encoding the TAF1 RNA polymerase II, TATA box-binding protein-associated factor, 250kDa.

Diagnostic methods
Diagnosis is based on clinical and neuroimaging findings (of postsynaptic striatal and presynaptic nigrostriatal involvement), as well as having a positive family history compatible with X-linked inheritance and maternal Panay Island ancestral roots. MRI usually shows no abnormalities. Molecular genetic testing can confirm the diagnosis by identifying a TAF1 mutation. Preliminary results from a pilot study indicate olfactory dysfunction in XDP, therefore olfactory testing may also support diagnosis.

Differential diagnosis
Differential diagnoses include Parkinson's disease, hereditary essential tremor, dopa-responsive dystonia and Parkinson-plus syndromes.

Antenatal diagnosis
Prenatal diagnosis is possible in families with a known TAF1 mutation.

Genetic counseling
XDP is inherited in an X-linked recessive manner and genetic counseling is recommended. Males with XDP pass the mutation to all of their daughters and none of their sons, whereas female carriers have a 50% chance of passing the mutation to their offspring. Rare de novo mutations have been reported.

Management and treatment
There is no cure for XDP. Treatment involves the use of pharmacological agents and offers only temporary or partial relief. In the early stages of dystonia, benzodiazepines and anticholinergic agents may be effective, especially in combination. Botulinum toxin injections may relieve focal dystonia. Tetrabenazine and zolpidem can improve dystonia once it becomes generalized or multifocal. Those with pure parkinsonism may be responsive to levodopa. Deep brain stimulation has shown promise in a few cases with advanced disease refractory to medication. Periodic swallowing evaluation is recommended, especially in those with dysphagia. Physical therapy may be helpful. Psychological counseling should be offered to patients and their families.

Prognosis
Prognosis is phenotype-dependent. Those with pure parkinsonism have the best prognosis, while those with a combination of parkinsonism followed by the development of orobuccolingual and cervical dystonia, 1-2 years after disease onset, have the worst prognosis, usually becoming bedridden with a reduced life expectancy.

Visit the Orphanet disease page for more resources.

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
30%-79% of people have these symptoms
Blepharospasm
Eyelid spasm
Eyelid twitching
Involuntary closure of eyelid
Spontaneous closure of eyelid

[ more ]

0000643
Bradykinesia
Slow movements
Slowness of movements

[ more ]

0002067
Chorea
0002072
Hand tremor
Tremor of hand
Tremor of hands
tremors in hands

[ more ]

0002378
Myoclonus
0001336
Parkinsonism with favorable response to dopaminergic medication
0002548
Postural instability
Balance impairment
0002172
Progressive extrapyramidal muscular rigidity
0007158
Resting tremor
Tremor at rest
0002322
Shuffling gait
Shuffled walk
0002362
Torsion dystonia
0001304
5%-29% of people have these symptoms
Aspiration pneumonia
0011951
Difficulty walking
Difficulty in walking
0002355
Frequent falls
0002359
Impaired oropharyngeal swallow response
0031162
Laryngeal stridor
0006511
Limb dystonia
0002451
Protruding tongue
Prominent tongue
Tongue sticking out of mouth

[ more ]

0010808
Percent of people who have these symptoms is not available through HPO
Adult onset
Symptoms begin in adulthood
0003581
Tremor
0001337
X-linked recessive inheritance
0001419

Diagnosis

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • MedlinePlus Genetics contains information on X-linked dystonia-parkinsonism/Lubag. This website is maintained by the National Library of Medicine.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss X-linked dystonia-parkinsonism/Lubag. Click on the link to view a sample search on this topic.