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Cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss syndrome(CAPOS)

MedGen UID:
318633
Concept ID:
C1832466
Disease or Syndrome
Synonyms: CAPOS; CAPOS syndrome; Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorinural hearing loss; CEREBELLAR ATAXIA, AREFLEXIA, PES CAVUS, OPTIC ATROPHY, AND SENSORINEURAL HEARING LOSS
SNOMED CT: Cerebellar ataxia, areflexia, pes cavus, optic atrophy, sensorineural hearing loss syndrome (720634003); CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, sensorineural hearing loss) syndrome (720634003)
Modes of inheritance:
Autosomal dominant inheritance
MedGen UID:
141047
Concept ID:
C0443147
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele.
Mitochondrial inheritance
MedGen UID:
165802
Concept ID:
C0887941
Genetic Function
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on the mitochondrial genome. Because the mitochondrial genome is essentially always maternally inherited, a mitochondrial condition can only be transmitted by females, although the condition can affect both sexes. The proportion of mutant mitochondria can vary (heteroplasmy).
 
Gene (location): ATP1A3 (19q13.2)
 
Monarch Initiative: MONDO:0011038
OMIM®: 601338
Orphanet: ORPHA1171

Disease characteristics

Excerpted from the GeneReview: ATP1A3-Related Neurologic Disorders
ATP1A3-related neurologic disorders represent a clinical continuum in which at least three distinct phenotypes have been delineated: rapid-onset dystonia-parkinsonism (RDP); alternating hemiplegia of childhood (ACH); and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS). However, some affected individuals have intermediate phenotypes or only a few features that do not fit well into one of these major phenotypes. RDP has been characterized by: abrupt onset of dystonia over days to weeks with parkinsonism (primarily bradykinesia and postural instability); common bulbar involvement; and absence or minimal response to an adequate trial of L-dopa therapy, with few exceptions. Often fever, physiologic stress, or alcoholic binges trigger the onset of symptoms. After their initial appearance, symptoms often stabilize with little improvement; occasionally second episodes occur with abrupt worsening of symptoms. Rarely, affected individuals have reported a more gradual onset of symptoms over weeks to months. Anxiety, depression, and seizures have been reported. Age of onset ranges from four to 55 years, although a childhood variation of RDP with onset between ages nine and 14 months has been reported. AHC is a complex neurodevelopmental syndrome most frequently manifesting in infancy or early childhood with paroxysmal episodic neurologic dysfunction including alternating hemiparesis or dystonia, quadriparesis, seizure-like episodes, and oculomotor abnormalities. Episodes can last for minutes, hours, days, or even weeks. Remission of symptoms occurs with sleep and immediately after awakening. Over time, persistent neurologic deficits including oculomotor apraxia, ataxia, choreoathetosis, dystonia, parkinsonism, and cognitive and behavioral dysfunction develop in the majority of those affected; more than 50% develop epilepsy in addition to their episodic movement disorder phenotype. CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) syndrome is characterized by episodes of ataxic encephalopathy and/or weakness during and after a febrile illness. Onset is between ages six months and four years. Some acute symptoms resolve; progression of sensory losses and severity vary. [from GeneReviews]
Authors:
Allison Brashear  |  Kathleen J Sweadner  |  Jared F Cook, et. al.   view full author information

Additional description

From OMIM
Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) is an autosomal dominant neurologic disorder characterized by early-childhood onset of recurrent episodes of acute ataxic encephalopathy associated with febrile illnesses. These acute episodes tend to decrease with time, but the neurologic sequelae are permanent and progressive, resulting in gait and limb ataxia and areflexia. Affected individuals also develop progressive visual impairment due to optic atrophy and sensorineural hearing loss beginning in childhood. More variable features include abnormal eye movements, pes cavus, and dysphagia (summary by Demos et al., 2014).  http://www.omim.org/entry/601338

Clinical features

From HPO
Urinary urgency
MedGen UID:
39315
Concept ID:
C0085606
Finding
Urge incontinence is the strong, sudden need to urinate.
Pes cavus
MedGen UID:
675590
Concept ID:
C0728829
Congenital Abnormality
An increase in height of the medial longitudinal arch of the foot that does not flatten on weight bearing (i.e., a distinctly hollow form of the sole of the foot when it is bearing weight).
Wolff-Parkinson-White pattern
MedGen UID:
12162
Concept ID:
C0043202
Disease or Syndrome
Wolff-Parkinson-White syndrome is a condition characterized by abnormal electrical pathways in the heart that cause a disruption of the heart's normal rhythm (arrhythmia).\n\nThe heartbeat is controlled by electrical signals that move through the heart in a highly coordinated way. A specialized cluster of cells called the atrioventricular node conducts electrical impulses from the heart's upper chambers (the atria) to the lower chambers (the ventricles). Impulses move through the atrioventricular node during each heartbeat, stimulating the ventricles to contract slightly later than the atria.\n\nPeople with Wolff-Parkinson-White syndrome are born with an extra connection in the heart, called an accessory pathway, that allows electrical signals to bypass the atrioventricular node and move from the atria to the ventricles faster than usual. The accessory pathway may also transmit electrical impulses abnormally from the ventricles back to the atria. This extra connection can disrupt the coordinated movement of electrical signals through the heart, leading to an abnormally fast heartbeat (tachycardia) and other changes in heart rhythm. Resulting symptoms include dizziness, a sensation of fluttering or pounding in the chest (palpitations), shortness of breath, and fainting (syncope). In rare cases, arrhythmias associated with Wolff-Parkinson-White syndrome can lead to cardiac arrest and sudden death. The most common arrhythmia associated with Wolff-Parkinson-White syndrome is called paroxysmal supraventricular tachycardia.\n\nComplications of Wolff-Parkinson-White syndrome can occur at any age, although some individuals born with an accessory pathway in the heart never experience any health problems associated with the condition.\n\nWolff-Parkinson-White syndrome often occurs with other structural abnormalities of the heart or underlying heart disease. The most common heart defect associated with the condition is Ebstein anomaly, which affects the valve that allows blood to flow from the right atrium to the right ventricle (the tricuspid valve). Additionally, the heart rhythm problems associated with Wolff-Parkinson-White syndrome can be a component of several other genetic syndromes, including hypokalemic periodic paralysis (a condition that causes episodes of extreme muscle weakness), Pompe disease (a disorder characterized by the storage of excess glycogen), Danon disease (a condition that weakens the heart and skeletal muscles and causes intellectual disability), and tuberous sclerosis complex (a condition that results in the growth of noncancerous tumors in many parts of the body).
Dysphagia
MedGen UID:
41440
Concept ID:
C0011168
Disease or Syndrome
Difficulty in swallowing.
Sensorineural hearing loss disorder
MedGen UID:
9164
Concept ID:
C0018784
Disease or Syndrome
A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
Hearing impairment
MedGen UID:
235586
Concept ID:
C1384666
Disease or Syndrome
A decreased magnitude of the sensory perception of sound.
Progressive sensorineural hearing impairment
MedGen UID:
335894
Concept ID:
C1843156
Disease or Syndrome
A progressive form of sensorineural hearing impairment.
Cerebellar ataxia
MedGen UID:
849
Concept ID:
C0007758
Disease or Syndrome
Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).
Dysarthria
MedGen UID:
8510
Concept ID:
C0013362
Mental or Behavioral Dysfunction
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.
Dystonic disorder
MedGen UID:
3940
Concept ID:
C0013421
Sign or Symptom
An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk.
Hemiparesis
MedGen UID:
6783
Concept ID:
C0018989
Finding
Loss of strength in the arm, leg, and sometimes face on one side of the body. Hemiplegia refers to a complete loss of strength, whereas hemiparesis refers to an incomplete loss of strength.
Seizure
MedGen UID:
20693
Concept ID:
C0036572
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Bradykinesia
MedGen UID:
115925
Concept ID:
C0233565
Sign or Symptom
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).
Areflexia
MedGen UID:
115943
Concept ID:
C0234146
Finding
Absence of neurologic reflexes such as the knee-jerk reaction.
Dysmetria
MedGen UID:
68583
Concept ID:
C0234162
Finding
A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements.
Reduced consciousness
MedGen UID:
65877
Concept ID:
C0234428
Finding
Abnormally diminished level of attention, responsiveness, or wakefulness.
Truncal ataxia
MedGen UID:
96535
Concept ID:
C0427190
Sign or Symptom
Truncal ataxia is a sign of ataxia characterized by instability of the trunk. It usually occurs during sitting.
Incoordination
MedGen UID:
141714
Concept ID:
C0520966
Finding
Gait ataxia
MedGen UID:
155642
Concept ID:
C0751837
Sign or Symptom
A type of ataxia characterized by the impairment of the ability to coordinate the movements required for normal walking. Gait ataxia is characteirzed by a wide-based staggering gait with a tendency to fall.
Autistic behavior
MedGen UID:
163547
Concept ID:
C0856975
Mental or Behavioral Dysfunction
Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior.
Peripheral axonal neuropathy
MedGen UID:
266071
Concept ID:
C1263857
Disease or Syndrome
An abnormality characterized by disruption of the normal functioning of peripheral axons.
Hereditary episodic ataxia
MedGen UID:
314033
Concept ID:
C1720189
Disease or Syndrome
Periodic spells of incoordination and imbalance, that is, episodes of ataxia typically lasting from 10 minutes to several hours or days.
Postural instability
MedGen UID:
334529
Concept ID:
C1843921
Finding
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.
Undetectable visual evoked potentials
MedGen UID:
376697
Concept ID:
C1850069
Finding
Arm dystonia
MedGen UID:
1671069
Concept ID:
C4732776
Finding
A type of dystonia (abnormally increased muscular tone causing fixed abnormal postures) that affects muscles of the arms.
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Muscle weakness
MedGen UID:
57735
Concept ID:
C0151786
Finding
Reduced strength of muscles.
Episodic generalized hypotonia
MedGen UID:
870528
Concept ID:
C4024976
Anatomical Abnormality
The occurrence of repeated episodes of generalized muscular hypotonia.
Nystagmus
MedGen UID:
45166
Concept ID:
C0028738
Disease or Syndrome
Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.
Optic atrophy
MedGen UID:
18180
Concept ID:
C0029124
Disease or Syndrome
Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy.
Blindness
MedGen UID:
99138
Concept ID:
C0456909
Disease or Syndrome
Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation.
Progressive visual loss
MedGen UID:
326867
Concept ID:
C1839364
Finding
A reduction of previously attained ability to see.
Visual impairment
MedGen UID:
777085
Concept ID:
C3665347
Finding
Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery.
Visual loss
MedGen UID:
784038
Concept ID:
C3665386
Finding
Loss of visual acuity (implying that vision was better at a certain time point in life). Otherwise the term reduced visual acuity should be used (or a subclass of that).

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
Follow this link to review classifications for Cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss syndrome in Orphanet.

Recent clinical studies

Diagnosis

Vezyroglou A, Akilapa R, Barwick K, Koene S, Brownstein CA, Holder-Espinasse M, Fry AE, Németh AH, Tofaris GK, Hay E, Hughes I, Mansour S, Mordekar SR, Splitt M, Turnpenny PD, Demetriou D, Koopmann TT, Ruivenkamp CAL, Agrawal PB, Carr L, Clowes V, Ghali N, Holder SE, Radley J, Male A, Sisodiya SM, Kurian MA, Cross JH, Balasubramanian M
Neurology 2022 Oct 4;99(14):e1511-e1526. Epub 2022 Jul 18 doi: 10.1212/WNL.0000000000200927. PMID: 36192182Free PMC Article

Clinical prediction guides

Vezyroglou A, Akilapa R, Barwick K, Koene S, Brownstein CA, Holder-Espinasse M, Fry AE, Németh AH, Tofaris GK, Hay E, Hughes I, Mansour S, Mordekar SR, Splitt M, Turnpenny PD, Demetriou D, Koopmann TT, Ruivenkamp CAL, Agrawal PB, Carr L, Clowes V, Ghali N, Holder SE, Radley J, Male A, Sisodiya SM, Kurian MA, Cross JH, Balasubramanian M
Neurology 2022 Oct 4;99(14):e1511-e1526. Epub 2022 Jul 18 doi: 10.1212/WNL.0000000000200927. PMID: 36192182Free PMC Article

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