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Spinocerebellar ataxia type 21(SCA21)

MedGen UID:
375311
Concept ID:
C1843891
Disease or Syndrome
Synonym: SCA21
SNOMED CT: Spinocerebellar ataxia type 21 (718774001)
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.
 
Gene (location): TMEM240 (1p36.33)
 
Monarch Initiative: MONDO:0011833
OMIM®: 607454
Orphanet: ORPHA98773

Definition

Spinocerebellar ataxia-21 (SCA21) is an autosomal dominant neurologic disorder characterized by onset in the first decades of life of slowly progressive cerebellar ataxia, which is associated with cognitive impairment in most patients (summary by Delplanque et al., 2014). For a general discussion of autosomal dominant spinocerebellar ataxia, see SCA1 (164400). [from OMIM]

Clinical features

From HPO
Aggressive behavior
MedGen UID:
1375
Concept ID:
C0001807
Individual Behavior
Aggressive behavior can denote verbal aggression, physical aggression against objects, physical aggression against people, and may also include aggression towards oneself.
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.
Impulsivity
MedGen UID:
43850
Concept ID:
C0021125
Mental or Behavioral Dysfunction
Acting on the spur of the moment in response to immediate stimuli; acting on a momentary basis without a plan or consideration of outcomes; difficulty establishing or following plans; a sense of urgency and self-harming behavior under emotional distress.
Akinesia
MedGen UID:
43218
Concept ID:
C0085623
Finding
Inability to initiate changes in activity or movement and to perform ordinary volitional movements rapidly and easily.
Apathy
MedGen UID:
39083
Concept ID:
C0085632
Mental or Behavioral Dysfunction
An emotional state of indifference characterized by a lack of interest or concern.
Abnormality of extrapyramidal motor function
MedGen UID:
115941
Concept ID:
C0234133
Sign or Symptom
A neurological condition related to lesions of the basal ganglia leading to typical abnormalities including akinesia (inability to initiate changes in activity and perform volitional movements rapidly and easily), muscular rigidity (continuous contraction of muscles with constant resistance to passive movement), chorea (widespread arrhythmic movements of a forcible, rapid, jerky, and restless nature), athetosis (inability to sustain the muscles of the fingers, toes, or other group of muscles in a fixed position), and akathisia (inability to remain motionless).
Dysgraphia
MedGen UID:
115942
Concept ID:
C0234144
Mental or Behavioral Dysfunction
A writing disability in the absence of motor or sensory deficits of the upper extremities, resulting in an impairment in the ability to write regardless of the ability to read and not due to intellectual impairment.
Postural tremor
MedGen UID:
66696
Concept ID:
C0234378
Sign or Symptom
A type of tremors that is triggered by holding a limb in a fixed position.
Mental deterioration
MedGen UID:
66713
Concept ID:
C0234985
Mental or Behavioral Dysfunction
Loss of previously present mental abilities, generally in adults.
Scanning speech
MedGen UID:
116113
Concept ID:
C0240952
Mental or Behavioral Dysfunction
An abnormal pattern of speech in which the words are as if measured or scanned; there is a pause after every syllable, and the syllables themselves are pronounced slowly.
Parkinsonism
MedGen UID:
66079
Concept ID:
C0242422
Disease or Syndrome
Characteristic neurologic anomaly resulting from degeneration of dopamine-generating cells in the substantia nigra, a region of the midbrain, characterized clinically by shaking, rigidity, slowness of movement and difficulty with walking and gait.
Cognitive impairment
MedGen UID:
90932
Concept ID:
C0338656
Mental or Behavioral Dysfunction
Abnormal cognition with deficits in thinking, reasoning, or remembering.
Progressive cerebellar ataxia
MedGen UID:
140727
Concept ID:
C0393525
Disease or Syndrome
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Hyporeflexia
MedGen UID:
195967
Concept ID:
C0700078
Finding
Reduction of neurologic reflexes such as the knee-jerk reaction.
Cerebellar atrophy
MedGen UID:
196624
Concept ID:
C0740279
Disease or Syndrome
Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event.
Limb ataxia
MedGen UID:
196692
Concept ID:
C0750937
Finding
A kind of ataxia that affects movements of the extremities.
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.
Intellectual disability
MedGen UID:
811461
Concept ID:
C3714756
Mental or Behavioral Dysfunction
Subnormal intellectual functioning which originates during the developmental period. Intellectual disability, previously referred to as mental retardation, has been defined as an IQ score below 70.
Delayed CNS myelination
MedGen UID:
867393
Concept ID:
C4021758
Anatomical Abnormality
Delayed myelination in the central nervous system.
Intention tremor
MedGen UID:
1642960
Concept ID:
C4551520
Sign or Symptom
A type of kinetic tremor that occurs during target directed movement is called intention tremor. That is, an oscillatory cerebellar ataxia that tends to be absent when the limbs are inactive and during the first part of voluntary movement but worsening as the movement continues and greater precision is required (e.g., in touching a target such as the patient's nose or a physician's finger).
Cogwheel rigidity
MedGen UID:
57469
Concept ID:
C0151564
Sign or Symptom
A type of rigidity in which a muscle responds with cogwheellike jerks to the use of constant force in bending the limb (i.e., it gives way in little, repeated jerks when the muscle is passively stretched).
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.
Strabismus
MedGen UID:
21337
Concept ID:
C0038379
Disease or Syndrome
A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error.
Opsoclonus
MedGen UID:
116616
Concept ID:
C0242567
Disease or Syndrome
Bursts of large-amplitude multidirectional saccades without intersaccadic interval
Hypermetric saccades
MedGen UID:
140835
Concept ID:
C0423083
Finding
A saccade that overshoots the target with the dynamic saccade.
Slow saccadic eye movements
MedGen UID:
232942
Concept ID:
C1321329
Finding
An abnormally slow velocity of the saccadic eye movements.
Microsaccadic pursuit
MedGen UID:
334855
Concept ID:
C1843892
Finding

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVSpinocerebellar ataxia type 21
Follow this link to review classifications for Spinocerebellar ataxia type 21 in Orphanet.

Professional guidelines

PubMed

Zesiewicz TA, Wilmot G, Kuo SH, Perlman S, Greenstein PE, Ying SH, Ashizawa T, Subramony SH, Schmahmann JD, Figueroa KP, Mizusawa H, Schöls L, Shaw JD, Dubinsky RM, Armstrong MJ, Gronseth GS, Sullivan KL
Neurology 2018 Mar 6;90(10):464-471. Epub 2018 Feb 9 doi: 10.1212/WNL.0000000000005055. PMID: 29440566Free PMC Article
Pareyson D, Gellera C, Castellotti B, Antonelli A, Riggio MC, Mazzucchelli F, Girotti F, Pietrini V, Mariotti C, Di Donato S
J Neurol 1999 May;246(5):389-93. doi: 10.1007/s004150050369. PMID: 10399872
Schöls L, Gispert S, Vorgerd M, Menezes Vieira-Saecker AM, Blanke P, Auburger G, Amoiridis G, Meves S, Epplen JT, Przuntek H, Pulst SM, Riess O
Arch Neurol 1997 Sep;54(9):1073-80. doi: 10.1001/archneur.1997.00550210011007. PMID: 9311350

Recent clinical studies

Diagnosis

Burdekin ED, Fogel BL, Jeste SS, Martinez J, Rexach JE, DiStefano C, Hyde C, Safari T, Wilson RB
J Child Neurol 2020 Dec;35(14):953-962. Epub 2020 Jul 24 doi: 10.1177/0883073820943488. PMID: 32705938Free PMC Article
Zeng S, Zeng J, He M, Zeng X, Zhou Y, Liu Z, Xia K, Pan Q, Jiang H, Shen L, Yan X, Tang B, Wang J
Sci Rep 2016 Jan 27;6:19897. doi: 10.1038/srep19897. PMID: 26813285Free PMC Article

Prognosis

Traschütz A, van Gaalen J, Oosterloo M, Vreeburg M, Kamsteeg EJ, Deininger N, Rieß O, Reimold M, Haack T, Schöls L, van de Warrenburg BP, Synofzik M
Parkinsonism Relat Disord 2019 May;62:215-220. Epub 2018 Nov 29 doi: 10.1016/j.parkreldis.2018.11.027. PMID: 30522958

Clinical prediction guides

Traschütz A, van Gaalen J, Oosterloo M, Vreeburg M, Kamsteeg EJ, Deininger N, Rieß O, Reimold M, Haack T, Schöls L, van de Warrenburg BP, Synofzik M
Parkinsonism Relat Disord 2019 May;62:215-220. Epub 2018 Nov 29 doi: 10.1016/j.parkreldis.2018.11.027. PMID: 30522958

Recent systematic reviews

Traschütz A, van Gaalen J, Oosterloo M, Vreeburg M, Kamsteeg EJ, Deininger N, Rieß O, Reimold M, Haack T, Schöls L, van de Warrenburg BP, Synofzik M
Parkinsonism Relat Disord 2019 May;62:215-220. Epub 2018 Nov 29 doi: 10.1016/j.parkreldis.2018.11.027. PMID: 30522958

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