Spinocerebellar ataxia type 26(SCA26)

MedGen UID:: 373077
•Concept ID:: C1836395
•: Disease or Syndrome

Synonym:	SCA26
SNOMED CT:	Spinocerebellar ataxia type 26 (718769009)
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. Autosomal dominant inheritance (Orphanet)

Gene (location): Gene(s) directly associated with this condition or phenotype.	EEF2 (19p13.3)

Monarch Initiative:	MONDO:0012246
OMIM®:	609306
Orphanet:	ORPHA101112

Definition

A very rare subtype of autosomal dominant cerebellar ataxia type 3 with characteristics of late-onset and slowly progressive cerebellar signs (gait ataxia) and eye movement abnormalities. To date, only 23 affected patients have been described from one American family of Norwegian descent. Disease onset occurs between the ages of 26-60. A candidate gene has recently been identified as the eukaryotic translation elongation factor 2 (EEF2) gene, located on chromosome 19p13.3. Inherited autosomal dominantly. [from SNOMEDCT_US]

Clinical features

From HPO

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.

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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.

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Incoordination

MedGen UID:: 141714
•Concept ID:: C0520966
•: Finding

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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.

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Limb ataxia

MedGen UID:: 196692
•Concept ID:: C0750937
•: Finding

A kind of ataxia that affects movements of the extremities.

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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.

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Nystagmus