MDT1 Flashcards
Muscular dystrophies
Encompass a range of disorders involving muscle weakness
Myotonic dystrophy type 1 (DM1)
Also known as Steinert’s disease
Progressive
Multisystemic disease
Systems affected in DM1
Muscle
Nervous system
Endocrine
Respiratory
Immune
Skeletal muscle
Reproductive systems
GIT
Autosomal dominant disorder characterised by…..
Myotonia
Inability to relax muscles following contraction
Uncontrolled muscle contraction including cardiac muscle
Respiratory changes
Early death caused by
Cardiorespiratory failure
Cognitive changes associated with DM1
Apathy, OCD, autistic-like traits
DM1 affects…
1 in 8000 people
Most common adult form of muscular dystrophy
Common symptoms
Drooping face and neck muscles
Difficulty swallowing
Cataracts
Weight loss
Symptoms vary throughout disease progression
DM1 occurs as a result of
CTG repeat length expansion in the DMPK gene
Meola and Cardani
Devised ranking system based on number of DMPK repeat lengths and age of onset in order to predict disease severity
Congential DM1
Typically results in repeat lengths of more than 1000 trinucleotides
Not considered most severe
CTG repeats increase during life in correlation with DM1 symptoms
Childhood onset (1-10 yo)
50-1000 repeats
Often not diagnosed with DM1
Common age of diagnosis
10-30 yo
Late onset (20-70 yo)
Mild dystonia
50-100 repeat lengths
Full length (85kDa) DMPK
Nuclear envelope stability
Lipid bilayer enclosing eukaryotic nucleus