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Autosomal recessive spinocerebellar ataxia 18(SCAR18)

MedGen UID:
863942
Concept ID:
C4015505
Disease or Syndrome
Synonyms: SCAR18; SPINOCEREBELLAR ATAXIA, AUTOSOMAL RECESSIVE 18
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
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 individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
 
Gene (location): GRID2 (4q22.1-22.2)
 
Monarch Initiative: MONDO:0014530
OMIM®: 616204
Orphanet: ORPHA363432

Definition

Autosomal recessive spinocerebellar ataxia-18 (SCAR18) is a neurologic disorder characterized by delayed psychomotor development, severely impaired gait due to cerebellar ataxia, ocular movement abnormalities, and intellectual disability. Brain imaging shows progressive cerebellar atrophy (summary by Hills et al., 2013). [from OMIM]

Clinical features

From HPO
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.
Babinski sign
MedGen UID:
19708
Concept ID:
C0034935
Finding
Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract.
Hyperreflexia
MedGen UID:
57738
Concept ID:
C0151889
Finding
Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles.
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.
Dysdiadochokinesis
MedGen UID:
115975
Concept ID:
C0234979
Sign or Symptom
A type of ataxia characterized by the impairment of the ability to perform rapidly alternating movements, such as pronating and supinating his or her hand on the dorsum of the other hand as rapidly as possible.
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.
Delayed speech and language development
MedGen UID:
105318
Concept ID:
C0454644
Finding
A degree of language development that is significantly below the norm for a child of a specified age.
Incoordination
MedGen UID:
141714
Concept ID:
C0520966
Finding
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.
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.
Cerebellar vermis atrophy
MedGen UID:
149271
Concept ID:
C0742028
Disease or Syndrome
Wasting (atrophy) of the vermis of cerebellum.
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.
Oculomotor apraxia
MedGen UID:
483686
Concept ID:
C3489733
Disease or Syndrome
Ocular motor apraxia is a deficiency in voluntary, horizontal, lateral, fast eye movements (saccades) with retention of slow pursuit movements. The inability to follow objects visually is often compensated by head movements. There may be decreased smooth pursuit, and cancelation of the vestibulo-ocular reflex.
Intellectual disability
MedGen UID:
811461
Concept ID:
C3714756
Mental or Behavioral Dysfunction
Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.
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.
Flexion contracture
MedGen UID:
83069
Concept ID:
C0333068
Anatomical Abnormality
A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints.
Esotropia
MedGen UID:
4550
Concept ID:
C0014877
Disease or Syndrome
A form of strabismus with one or both eyes turned inward ('crossed') to a relatively severe degree, usually defined as 10 diopters or more.
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.
Horizontal nystagmus
MedGen UID:
124399
Concept ID:
C0271385
Disease or Syndrome
Nystagmus consisting of horizontal to-and-fro eye movements.
Optic disc pallor
MedGen UID:
108218
Concept ID:
C0554970
Finding
A pale yellow discoloration of the optic disc (the area of the optic nerve head in the retina). The optic disc normally has a pinkish hue with a central yellowish depression.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVAutosomal recessive spinocerebellar ataxia 18

Professional guidelines

PubMed

Beaudin M, Matilla-Dueñas A, Soong BW, Pedroso JL, Barsottini OG, Mitoma H, Tsuji S, Schmahmann JD, Manto M, Rouleau GA, Klein C, Dupre N
Cerebellum 2019 Dec;18(6):1098-1125. doi: 10.1007/s12311-019-01052-2. PMID: 31267374Free PMC Article
Levy A, Lang AE
Mov Disord 2018 Aug;33(8):1238-1247. Epub 2018 Feb 13 doi: 10.1002/mds.27319. PMID: 29436738

Recent clinical studies

Etiology

Zheng Q, Tang J, Aicher A, Bou Kheir T, Sabanovic B, Ananthanarayanan P, Reina C, Chen M, Gu JM, He B, Alcala S, Behrens D, Lawlo RT, Scarpa A, Hidalgo M, Sainz B Jr, Sancho P, Heeschen C
J Exp Clin Cancer Res 2023 Nov 28;42(1):323. doi: 10.1186/s13046-023-02883-y. PMID: 38012687Free PMC Article
Iodice A, Spagnoli C, Cangini M, Soliani L, Rizzi S, Salerno GG, Frattini D, Pisani F, Fusco C
J Clin Neurosci 2020 Jul;77:232-234. Epub 2020 May 6 doi: 10.1016/j.jocn.2020.05.008. PMID: 32387255
Beaudin M, Matilla-Dueñas A, Soong BW, Pedroso JL, Barsottini OG, Mitoma H, Tsuji S, Schmahmann JD, Manto M, Rouleau GA, Klein C, Dupre N
Cerebellum 2019 Dec;18(6):1098-1125. doi: 10.1007/s12311-019-01052-2. PMID: 31267374Free PMC Article
Ebrahimi-Fakhari D
Neuropediatrics 2018 Feb;49(1):18-25. Epub 2017 Nov 7 doi: 10.1055/s-0037-1608652. PMID: 29112993
Ruano L, Melo C, Silva MC, Coutinho P
Neuroepidemiology 2014;42(3):174-83. Epub 2014 Mar 5 doi: 10.1159/000358801. PMID: 24603320

Diagnosis

Balakrishnan S, Aggarwal S, Muthulakshmi M, Meena AK, Borgohain R, Mridula KR, Yareeda S, Ranganath P, Dalal A
Neurol India 2022 May-Jun;70(3):934-942. doi: 10.4103/0028-3886.349660. PMID: 35864621
Rezende Filho FM, Bremner F, Pedroso JL, de Andrade JBC, Marianelli BF, Lourenço CM, Marques-Júnior W, França MC Jr, Kok F, Sallum JMF, Parkinson MH, Barsottini OG, Giunti P
Mov Disord 2021 Sep;36(9):2027-2035. Epub 2021 Apr 23 doi: 10.1002/mds.28612. PMID: 33893680
Beaudin M, Matilla-Dueñas A, Soong BW, Pedroso JL, Barsottini OG, Mitoma H, Tsuji S, Schmahmann JD, Manto M, Rouleau GA, Klein C, Dupre N
Cerebellum 2019 Dec;18(6):1098-1125. doi: 10.1007/s12311-019-01052-2. PMID: 31267374Free PMC Article
Ruano L, Melo C, Silva MC, Coutinho P
Neuroepidemiology 2014;42(3):174-83. Epub 2014 Mar 5 doi: 10.1159/000358801. PMID: 24603320
Koutsis G, Kladi A, Karadima G, Houlden H, Wood NW, Christodoulou K, Panas M
J Neurol Sci 2014 Jan 15;336(1-2):87-92. Epub 2013 Oct 16 doi: 10.1016/j.jns.2013.10.012. PMID: 24209901

Therapy

Aghamohammadi A, Akrami SM, Yaghmaie M, Rezaei N, Azizi G, Yaseri M, Nosrati H, Zaki-Dizaji M
Sultan Qaboos Univ Med J 2018 Nov;18(4):e440-e446. Epub 2019 Mar 28 doi: 10.18295/squmj.2018.18.04.003. PMID: 30988961Free PMC Article
Zheng R, Zhao Y, Wu J, Wang Y, Liu JL, Zhou ZL, Zhou XT, Chen DN, Liao WH, Li JD
Mol Med Rep 2018 Jul;18(1):261-267. Epub 2018 May 3 doi: 10.3892/mmr.2018.8955. PMID: 29749493Free PMC Article
Reetz K, Dogan I, Costa AS, Dafotakis M, Fedosov K, Giunti P, Parkinson MH, Sweeney MG, Mariotti C, Panzeri M, Nanetti L, Arpa J, Sanz-Gallego I, Durr A, Charles P, Boesch S, Nachbauer W, Klopstock T, Karin I, Depondt C, vom Hagen JM, Schöls L, Giordano IA, Klockgether T, Bürk K, Pandolfo M, Schulz JB
Lancet Neurol 2015 Feb;14(2):174-82. Epub 2015 Jan 5 doi: 10.1016/S1474-4422(14)70321-7. PMID: 25566998
Rosini F, Federighi P, Pretegiani E, Piu P, Leigh RJ, Serra A, Federico A, Rufa A
PLoS One 2013;8(7):e69522. Epub 2013 Jul 22 doi: 10.1371/journal.pone.0069522. PMID: 23894498Free PMC Article
Mrissa N, Belal S, Hamida CB, Amouri R, Turki I, Mrissa R, Hamida MB, Hentati F
Neurology 2000 Apr 11;54(7):1408-14. doi: 10.1212/wnl.54.7.1408. PMID: 10751248

Prognosis

Zheng Q, Tang J, Aicher A, Bou Kheir T, Sabanovic B, Ananthanarayanan P, Reina C, Chen M, Gu JM, He B, Alcala S, Behrens D, Lawlo RT, Scarpa A, Hidalgo M, Sainz B Jr, Sancho P, Heeschen C
J Exp Clin Cancer Res 2023 Nov 28;42(1):323. doi: 10.1186/s13046-023-02883-y. PMID: 38012687Free PMC Article
Iodice A, Spagnoli C, Cangini M, Soliani L, Rizzi S, Salerno GG, Frattini D, Pisani F, Fusco C
J Clin Neurosci 2020 Jul;77:232-234. Epub 2020 May 6 doi: 10.1016/j.jocn.2020.05.008. PMID: 32387255
Zheng R, Zhao Y, Wu J, Wang Y, Liu JL, Zhou ZL, Zhou XT, Chen DN, Liao WH, Li JD
Mol Med Rep 2018 Jul;18(1):261-267. Epub 2018 May 3 doi: 10.3892/mmr.2018.8955. PMID: 29749493Free PMC Article
Levy A, Lang AE
Mov Disord 2018 Aug;33(8):1238-1247. Epub 2018 Feb 13 doi: 10.1002/mds.27319. PMID: 29436738
El Euch-Fayache G, Lalani I, Amouri R, Turki I, Ouahchi K, Hung WY, Belal S, Siddique T, Hentati F
Arch Neurol 2003 Jul;60(7):982-8. doi: 10.1001/archneur.60.7.982. PMID: 12873855

Clinical prediction guides

Zheng Q, Tang J, Aicher A, Bou Kheir T, Sabanovic B, Ananthanarayanan P, Reina C, Chen M, Gu JM, He B, Alcala S, Behrens D, Lawlo RT, Scarpa A, Hidalgo M, Sainz B Jr, Sancho P, Heeschen C
J Exp Clin Cancer Res 2023 Nov 28;42(1):323. doi: 10.1186/s13046-023-02883-y. PMID: 38012687Free PMC Article
Das S, Thomas M, Yoganathan S, Muthusamy K, Barney AM, A SSC, Dutta AK, A R, Mohan S, Danda S
Eur J Med Genet 2023 Jun;66(6):104766. Epub 2023 Apr 17 doi: 10.1016/j.ejmg.2023.104766. PMID: 37075885
Rezende Filho FM, Bremner F, Pedroso JL, de Andrade JBC, Marianelli BF, Lourenço CM, Marques-Júnior W, França MC Jr, Kok F, Sallum JMF, Parkinson MH, Barsottini OG, Giunti P
Mov Disord 2021 Sep;36(9):2027-2035. Epub 2021 Apr 23 doi: 10.1002/mds.28612. PMID: 33893680
Van Poucke M, Stee K, Sonck L, Stock E, Bosseler L, Van Dorpe J, Van Nieuwerburgh F, Deforce D, Peelman LJ, Van Ham L, Bhatti SFM, Broeckx BJG
Eur J Hum Genet 2019 Oct;27(10):1561-1568. Epub 2019 Jun 3 doi: 10.1038/s41431-019-0432-3. PMID: 31160700Free PMC Article
Zheng R, Zhao Y, Wu J, Wang Y, Liu JL, Zhou ZL, Zhou XT, Chen DN, Liao WH, Li JD
Mol Med Rep 2018 Jul;18(1):261-267. Epub 2018 May 3 doi: 10.3892/mmr.2018.8955. PMID: 29749493Free PMC Article

Recent systematic reviews

Ruano L, Melo C, Silva MC, Coutinho P
Neuroepidemiology 2014;42(3):174-83. Epub 2014 Mar 5 doi: 10.1159/000358801. PMID: 24603320

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