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Disease Profile

Dysequilibrium syndrome

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

Neonatal

ICD-10

G11.8

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)

DES; Cerebellar hypoplasia, VLDLR associated; VLDLRCH

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: 1766

Definition
Dysequilibrium syndrome (DES) is a non-progressive cerebellar disorder characterized by ataxia associated with an intellectual disability, delayed ambulation and cerebellar hypoplasia.

Epidemiology
To date, more than 50 individuals have been reported in the world literature.

Clinical description
DES is a congenital disorder characterized by nonprogressive cerebellar ataxia, associated with a moderate to profound intellectual disability and delayed ambulation. Gait can be either bipedal or quadrupedal. Additional features include hypotonia, lack of coordination, delayed motor development, seizures, dysarthria, strabismus, short stature and pes planus.

Etiology
Etiological subtypes of DES have been reported and include type 1 (CAMRQ1), 2 (CAMRQ2), 3 (CAMRQ3) and 4 (CAMRQ4) which are attributed to mutations in VLDLR (9p24), CA8 (8q12.1), WDR81 (17p13.3) and ATP8A2 (13q12) genes, respectively. VLDLR encodes the very low density lipoprotein receptor (VLDLR) which is involved in neuronal migration in the cerebral cortex and cerebellum. CA8 encodes a carbonic-anhydrase related protein, whose biological function is not yet fully understood. The function of WDR81 is still unknown. ATP8A2 encodes an ATPase which is mainly expressed in brain tissue, with the highest levels found in the cerebellum, and that may be critical for the developmental processes of the central nervous system.

Genetic counseling
Transmission is autosomal recessive. Genetic counseling should be offered to at-risk couples (both individuals are carriers of a disease-causing mutation) informing them of the 25% chance of having an affected child.

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
80%-99% of people have these symptoms
Ataxia
0001251
Gait disturbance
Abnormal gait
Abnormal walk
Impaired gait

[ more ]

0001288
Hyperreflexia
Increased reflexes
0001347
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249
Muscular hypotonia
Low or weak muscle tone
0001252
30%-79% of people have these symptoms
Cerebral palsy
0100021
Seizure
0001250
Short stature
Decreased body height
Small stature

[ more ]

0004322
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting

[ more ]

0003202
Strabismus
Cross-eyed
Squint
Squint eyes

[ more ]

0000486
5%-29% of people have these symptoms
Abnormality of vision
Abnormality of sight
Vision issue

[ more ]

0000504
Cataract
Clouding of the lens of the eye
Cloudy lens

[ more ]

0000518
Percent of people who have these symptoms is not available through HPO
Abnormality of metabolism/homeostasis
Laboratory abnormality
Metabolism abnormality

[ more ]

0001939
Autosomal recessive inheritance
0000007
Broad-based gait
Wide based walk
0002136
Cerebellar atrophy
Degeneration of cerebellum
0001272
Cerebellar hypoplasia
Small cerebellum
Underdeveloped cerebellum

[ more ]

0001321
Congenital onset
Symptoms present at birth
0003577
Delayed speech and language development
Deficiency of speech development
Delayed language development
Delayed speech
Delayed speech acquisition
Delayed speech development
Impaired speech and language development
Impaired speech development
Language delay
Language delayed
Language development deficit
Late-onset speech development
Poor language development
Speech and language delay
Speech and language difficulties
Speech delay

[ more ]

0000750
Dysarthria
Difficulty articulating speech
0001260
Dysdiadochokinesis
Difficulty performing quick and alternating movements
0002075
Dysmetria
Lack of coordination of movement
0001310
Gait ataxia
Inability to coordinate movements when walking
0002066
Gaze-evoked nystagmus
0000640
Generalized hypotonia
Decreased muscle tone
Low muscle tone

[ more ]

0001290
Global developmental delay
0001263
Hypoplasia of the brainstem
Small brainstem
Underdeveloped brainstem

[ more ]

0002365
Intention tremor
0002080
Nonprogressive
0003680
Pachygyria
Fewer and broader ridges in brain
0001302
Pes planus
Flat feet
Flat foot

[ more ]

0001763
Poor speech
0002465
Psychomotor retardation
0025356
Simplified gyral pattern
0009879
Truncal ataxia
Instability or lack of coordination of central trunk muscles
0002078

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.

In-Depth Information

  • 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 Dysequilibrium syndrome. Click on the link to view a sample search on this topic.