Myopathies Flashcards
What is muscular dystrophies
Group of genetic disorder characterised by progressive muscle weakness and degenration
Muscle mutations relating to structure and function
Have
Muscle fibre degenration
Inflammation
Calcium dysreguartion
Fibrosis and fatty infiltration
What is duchenne muscular dystrophy
Mutation in dystrophin gene, maintains structural integrity of muscles
Reduced function, muscle fibre damage in contraction.
Increase influx of ca2+ ions leading to muscular necrosis
Calcium toxicity
Proximally starts (shoulder, hips)
thenb affects distal
loss of ambulation by around age 12, with respiratory and cardiac muscle involvement contributing to a reduced life expectancy, typically into the early 20s or 30s.
Mc form of ,uscular dystrophy
Mc in boys
Becker muscular dystrophy is similar but less aggressive and starts age 20
What is Becker muscular dystrophy
Partially functional dysrophin
Some protection of muscle cell, disease is lower
Begin later in childhood or adolescents
loss of ambulation in the third or fourth decade of life. Cardiac involvement is also common, and patients may suffer from dilated cardiomyopathy as well as respiratory insufficiency.
What is Limb-Girdle Muscular Dystrophies (LGMD)
Large group of mutations of genes. Affect proteins involved in muscle contraction, membrane stabilisation, intracellular signalling
Muscle weakness
primarily affects the proximal muscles of the shoulders and hips, and progression may lead to severe disability. Depending on the subtype, the onset can vary from childhood to adulthood, with some forms having a relatively slow progression while others are more rapid.
What is myotonic dystrophy
RNA toxicity that disrupts functions of protein in muscle function
Muscle weakness, dystrophy, affects heart leading to arrhythmias), the eyes (cataracts), and the endocrine system (insulin resistance).
Severity determined on repeat expansion
Mild or congenital
Facioscapulohumeral Muscular Dystrophy (FSHD)
Deletion of a repeat region of a chromosome , causing toxins on muscle cells
Muscle necrosis and inflammation
Affects face, shoulder, upper arms.
Second decade of life
Slow progression
What is a channelopathy
Disordered related to abnormal ion passage within the muscle membrane ion channels
Variable mutations
Periodic paralyses as well as myotonic disorders
Mc paralysis episodes bilateral
What is McCardle disease
Lack of enzymes that assisted carbohydrates metabolism
People live say,Tom free a their cells have found different pathway to create energy power.
Symptoms can also be fatigue, exercise intolerance, muscle cramping, heart issue, disease affect respiratory organs
List congenital myopathies
Centronuclear: causes death from respiratory insufficiency i infants
Hypotonia, weakness
Central core disease: infancy and childhood.generlasuded weakness
Low muscle tone, floppies, muscle weakness and scoliosis. Muscles affected are proximal. Delay in crawling or walking. Autosomal Dominant pattern
Risk of malignant hyperthermia
List inflammatory myopathies
Acquired muscle disease. Muscle inflammation and weakness especially proximally. Autoimmune
Polymyositis: uncommon. T-cell mediated autoimmune attack on muscle fibres
Mc adults
Symmetrical proximal weakness, upper and lower extremeities
Mild dysphagia, myalgia and poly arthritis
Head drop, respiratory muscle weakness
Dermatomyositis : damage to muscle capillaries and skin. Proximal muscle weakness plus skin rash
How can acquired myopathy form
Muscle diseases that develop due to external factors
Hypothyroidism
Hyperthyroidism
Cushions syndrome
Diabetes mellitus
Vit d deficiency
Alcohol
Starting
Infections
Autoimmune diseases
Define myopathy
A disease of the muscle membrane ion which fibres do not function properly
Non-neurological
List types of myopathy
Inherited
Acquired
Metabolic or mitochondrial
Toxic
List metabolic myopathy
Inherited disorder
Affects biochemical pathways
Leads to exercise intolerance, muscle cramp, weakness
Glycogen storage disease. Issue in breakdown
Fatty acid oxidation disorder
Mitochondrial myopathies
What is muscular dystrophies
Inherited muscle disorder characterised by progressive weakness and degenration of skeletal muscle
Mutation in muscle structure, function or repair
