Neurogenetics Flashcards
(21 cards)
how is duchenne muscular dystrophy inherited
X linked recessive
what is the progression of disease like in duchenne muscular dystrophy
delay in motor development
onset of weakness by 3-4 years-pelvic and shoulder girdle
wheelchair bound by late teens
death from resp and cardiac muscle dysfunction in 20s/30s
what happens to calf muscles in DMD
calf hypertrophy
what deficiency is there in DMD
dystrophin deficiency
what causes the deficiency in dystrophin gene
in 70% there is a large scale deletion but in 30% there are point mutations, small insertions and deletion
how is DMD diagnosed
developmental delay in boys muscle weakness-Gower' sign and toe walking raised CK electromyography muscle biopsy molecular genetic testing
at what age does huntington disease usually present
between 30-50 years
what does huntingtons disease cause
involuntary movements
dementia
progression to severe dependency and death over 15-20 years
what are some of the early clinical signs of huntingtons disease
clumsiness agitation irritability apathy anxiety disinhibition delusions/hallucinations abnormal eye movements depression
what are some of the later clinical signs
dystonia involuntary movements trouble with balance and wlaking slow voluntary movements difficulty initiating movement inability to control speed and force of movement weight loss speech difficulties stubbornness
late clinical signs of huntingtons
rigidity bradykinesia severe chorea (less common) serious weight loss inability to walk inability to speak swallowing problems, danger of choking inability to care for oneself
what is the gene defect in huntingtons
CAG
what does CAG code for
glutamine
what is the pathology of Alzheimers
loss of cortical neurons neurofibrillary tangles (intracellular) senile plaques (extracellular)
what is contained in the senile plaques
extracellular protein deposits containing amyloid B protein
what is amyloid B protein a fragment of
the APP gene-amyloid precursor protein
what are the genetic aetiology of Alzheimers disease
an autosomal dominant trait in 5-10% of cases (early onset) down syndrome (onset in 3rd or 4th decade
where are the mutations in autosomal dominant Alzheimers
APPA mutations in chromosome 21
presenilin 1-chromosome 14
presenilin 2-chromosome 1
which apoE allele is associated with Alzheimer disease
e4 allele predisposes to Alzheimer disease with some clustering in families
which apoE allele is associated with longevity
e2
how is MS inherited
multifactorial with many genes contributing to a little risk
more common in individuals with certain MHC haplotypes
