Cerebellum Flashcards
(19 cards)
What are SCAs primarily caused by?
Large number of repeats of glutamine residues
SCAs are polyglutamine diseases associated with a polyQ sequence.
What is the one-letter designation for glutamine?
Q
Q represents the amino acid glutamine in the polyQ sequence.
What is the trinucleotide repeat associated with glutamine?
CAG
CAG is the codon for glutamine.
What is the threshold for symptoms in most forms of SCA?
Approx 35
This refers to the number of CAG repeats.
When was the first ataxia gene identified and what is it called?
1993, Spinocerebellar ataxia type 1 (SCA1)
SCA1 was the first identified ataxia gene.
How are the types of SCA numbered?
According to the order in which the gene was found
Later genes were designated SCA2, SCA3, etc.
What type of genetic inheritance is associated with Spinocerebellar ataxia?
Autosomal recessive and autosomal dominant
SCA can be caused by either a recessive or dominant gene.
How many types of Autosomal dominant cerebellar ataxia (ADCA) exist?
3 types
Type 1 ADCA is further divided into 3 subclasses.
What causes Subtype 1 of Type 1 ADCA?
CAG nucleotide repeats in the DNA
These repeats code for the amino acid glutamine.
What distinguishes Subtype 2 of Type 1 ADCA from Subtype 1?
CAG repeats in RNA, affecting gene expression
Subtype 2 does not code for proteins.
What causes Subtype 3 of Type 1 ADCA?
Different mutations and deletions in genes
This subtype has a different genetic basis.
What is Spinocerebellar ataxia (SCA)?
Progressive, degenerative, genetic disease
SCA has multiple types with no effective treatment or cure.
What is the usual diagnosis method for SCA?
SCA unidentified/unknown
A blood test is available for some types.
Who typically diagnoses SCA?
Neurologist
Diagnosis involves a physical exam, family history, MRI scan, and spinal tap.
What are common signs and symptoms of SCA?
Slowly progressive incoordination of gait, poor coordination, atrophy of the cerebellum
Symptoms include unsteady motion and impaired eye movements.
What types of hereditary ataxias are categorized by mode of inheritance?
Autosomal dominant, autosomal recessive, X-linked
These categories help classify the different types of hereditary ataxias.
Fill in the blank: SCA is caused by either a _______ or dominant gene.
recessive
This refers to the genetic inheritance patterns of SCA.
What is a typical characteristic of atrophy in SCA?
Atrophy of the cerebellum
This leads to various coordination issues.
What is the result of problems in controlling individual muscles and joints in SCA?
Complex tasks involving several parts of the body become challenging
Coordination issues affect overall motor skills.
