Spinocerebellar ataxia type 1

General Information (adopted from Orphanet):

Synonyms, Signs: OLIVOPONTOCEREBELLAR ATROPHY I
SPINOCEREBELLAR ATROPHY I
CEREBELLOPARENCHYMAL DISORDER I
OLIVOPONTOCEREBELLAR ATROPHY IV
MENZEL TYPE OPCA
OPCA IV
OPCA I
SCHUT-HAYMAKER TYPE OPCA
SCA1
CPD1
OPCA4
OPCA1
Number of Symptoms 48
OrphanetNr: 98755
OMIM Id: 164400
ICD-10: G11
UMLs: C0752120
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: 1.5 of 100 000 [Orphanet]
Inheritance: Autosomal dominant
[Orphanet]
Age of onset: All ages
[Orphanet]

Disease classification (adopted from Orphanet):

Parent Diseases: Autosomal dominant cerebellar ataxia type 1
 -Rare eye disease
 -Rare genetic disease
 -Rare neurologic disease
Huntington disease-like syndrome
 -Rare genetic disease
 -Rare neurologic disease

Symptom Information: Sort by abundance 

1
(HPO:0002839) Urinary bladder sphincter dysfunction 34 / 7739
2
(HPO:0001151) Impaired horizontal smooth pursuit 7 / 7739
3
(HPO:0000543) Optic disc pallor 67 / 7739
4
(HPO:0000514) Slow saccadic eye movements 21 / 7739
5
(HPO:0000641) Dysmetric saccades 10 / 7739
6
(HPO:0000648) Optic atrophy 238 / 7739
7
(HPO:0000623) Supranuclear ophthalmoplegia 5 / 7739
8
(HPO:0000640) Gaze-evoked nystagmus 27 / 7739
9
(HPO:0003487) Babinski sign 179 / 7739
10
(HPO:0007034) Generalized hyperreflexia 33 / 7739
11
(HPO:0001284) Areflexia 198 / 7739
12
(HPO:0001310) Dysmetria 76 / 7739
13
(HPO:0001260) Dysarthria 329 / 7739
14
(HPO:0001347) Hyperreflexia 363 / 7739
15
(HPO:0002168) Scanning speech 10 / 7739
16
(HPO:0003448) Decreased sensory nerve conduction velocity 1/9 [HPO:probinson] 9448569 IBIS 9 / 7739
17
(HPO:0007256) Abnormal pyramidal signs 116 / 7739
18
(HPO:0002073) Progressive cerebellar ataxia 27 / 7739
19
(HPO:0100543) Cognitive impairment 230 / 7739
20
(HPO:0003431) Decreased motor nerve conduction velocity 2/9 [HPO:probinson] 9448569 IBIS 51 / 7739
21
(HPO:0001257) Spasticity 251 / 7739
22
(HPO:0002072) Chorea 53 / 7739
23
(HPO:0009830) Peripheral neuropathy 206 / 7739
24
(HPO:0002495) Impaired vibratory sensation 26 / 7739
25
(HPO:0002267) Exaggerated startle response 42 / 7739
26
(HPO:0002070) Limb ataxia 41 / 7739
27
(HPO:0007078) Decreased amplitude of sensory action potentials 9/9 [HPO:probinson] 9448569 IBIS 5 / 7739
28
(HPO:0002015) Dysphagia 301 / 7739
29
(HPO:0002075) Dysdiadochokinesis 40 / 7739
30
(HPO:0002078) Truncal ataxia 41 / 7739
31
(HPO:0002071) Abnormality of extrapyramidal motor function 76 / 7739
32
(HPO:0001283) Bulbar palsy 31 / 7739
33
(HPO:0008947) Infantile muscular hypotonia 482 / 7739
34
(HPO:0003693) Distal amyotrophy 118 / 7739
35
(HPO:0001252) Muscular hypotonia 990 / 7739
36
(HPO:0010547) Muscle flaccidity 466 / 7739
37
(HPO:0001324) Muscle weakness 859 / 7739
38
(HPO:0002542) Olivopontocerebellar atrophy 11 / 7739
39
(HPO:0007263) Spinocerebellar atrophy 3 / 7739
40
(OMIM) Posterior column degeneration 2 / 7739
41
(HPO:0002503) Spinocerebellar tract degeneration 8 / 7739
42
(HPO:0002198) Dilated fourth ventricle 12 / 7739
43
(HPO:0000006) Autosomal dominant inheritance 2518 / 7739
44
(OMIM) Fasciculation-like movements 3 / 7739
45
(HPO:0003744) Genetic anticipation with paternal anticipation bias 2 / 7739
46
(HPO:0003581) Adult onset 117 / 7739
47
(OMIM) Cognitive impairment, mild 15 / 7739
48
(HPO:0007006) Dorsal column degeneration 2 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) The autosomal dominant cerebellar degenerative disorders are generally referred to as 'spinocerebellar ataxias,' (SCAs) even though 'spinocerebellar' is a hybrid term, referring to both clinical signs and neuroanatomical regions (Margolis, 2003). Neuropathologists have defined SCAs as cerebellar ataxias ...
Diagnosis OMIM Lucotte et al. (2001) demonstrated the feasibility of presymptomatic diagnosis in spinocerebellar ataxia-1. They studied a family in which the mean age of onset of the disorder was 38 years. Hitherto, presymptomatic testing for late-onset autosomal dominant disorders ...
Clinical Description OMIM Symptoms of SCA1 usually begin in the third or fourth decade of life, most often around age 30. In addition to cerebellar signs, there are upper motor neuron signs and extensor plantar responses. Involuntary choreiform movements may occur. ...
Genotype-Phenotype Correlations OMIM Schols et al. (1997) compared clinical, electrophysiologic, and magnetic resonance imaging (MRI) findings to identify phenotypic characteristics of genetically defined SCA subtypes. Slow saccades, hyporeflexia, myoclonus, and action tremor suggested SCA2. SCA3 patients frequently developed diplopia, severe spasticity ...
Molecular genetics OMIM Banfi et al. (1994) determined that the CAG trinucleotide repeat identified by Orr et al. (1993) in SCA1 occurs in the ataxin-1 gene (601556.0001).

- Genetic Anticipation

Chung et al. (1993) found that 63% ...

Population genetics OMIM Giunti et al. (1994) examined members of 73 families who were affected with a variety of autosomal dominant late-onset cerebellar ataxias for the trinucleotide repeat expansion associated with the SCA1 locus. The mutation was found in 19 of ...
Diagnosis GeneReviews The phenotypic manifestations of spinocerebellar ataxia type 1 (SCA1) are not specific; thus, the diagnosis of SCA1 rests on molecular genetic testing. ...
Clinical Description GeneReviews Spinocerebellar ataxia type 1 (SCA1) is characterized by ataxia, dysarthria, and eventual deterioration of bulbar functions [Klockgether et al 1998, Filla et al 2000]. Onset is typically in the third or fourth decade, although early onset in childhood has been documented [Currier et al 1972, Zoghbi et al 1988, Schöls et al 1997]. In adult-onset SCA1, the duration of illness from onset to death ranges from ten to 30 years; individuals with juvenile-onset disease (whose symptoms appear before age 13 years) show more rapid progression and more severe disease, and die before age 16 years [Zoghbi et al 1988]. ...
Genotype-Phenotype Correlations GeneReviews Probands. A strong correlation exists between the number of CAG repeats and severity of disease: the larger the CAG repeat, the earlier the onset and more severe the disease. However, the correlation is broad; only 50% to 70% of age at onset variance can be explained by CAG repeat size [Orr et al 1993, Schöls et al 1997, Stevanin et al 2000]. ...
Differential Diagnosis GeneReviews The inherited spinocerebellar ataxias (SCAs) are a heterogeneous group of neurologic disorders that defy easy differentiation on the basis of clinical criteria alone. Inter- and intrafamilial variability is too great to permit definitive classification without molecular genetic testing. See also Ataxia Overview. ...
Management GeneReviews To establish the extent of disease in an individual diagnosed with spinocerebellar ataxia type 1 (SCA1), the following evaluations are recommended:...
Molecular genetics GeneReviews Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED....