Organelle Diseases Flashcards
What organelle is progeria due to?
Nuclear envelop
What organelle is dyskeratosis congenita due to?
Ribosome
Describe dyskeratosis congenita
Mutation of the dyskerin gene which is involved in ribosome biogenesis: abnormal skin pigmentation w/ tan-to-gray hyperpigmented or hypopigmented patches in a mottled or reticulated pattern
Describe progeria
Premature aging in children leading to death linked to a mutation in the lamin A gene (messes up one of the parts of cell division)
What organelle is cystic fibrosis due to?
ER
Describe cystic fibrosis
Misfolding of the cystic fibrosis transmembrane regulator protein which is trapped in the ER and then degraded: deficit of this protein causes thick mucous in lungs
What organelle is congenital disorder of glycosylation syndrome due to?
Golgi
What was congenital disorder of glycosylation syndrome previously called?
Carbohydrate-deficient glycoprotein syndrome
Describe congenital disorder of glycosylation syndrome
Rare defect of metabolism where glycosylation of tissue proteins is deficient (inability to charge mannose to prepare it for glycosylation) with causes cerebellar and cerebral atrophy and psychomotor retardation
Symptoms: failure to thrive and mental retardation
What are lysosomal storage diseases?
50+ rare metabolic inherited diseases resulting from defects in lysosomal function
What organelle is peroxisomal disease due to?
Peroxisome
Describe peroxisomal disease
Neurological diseases that results from defects in biogenesis of peroxisomes or in enzymes in them
What organelle is adrenoleukodystrophy (ALD) due to?
Peroxisome
Describe adrenoleukodystrophy (ALD)
Disorder of peroxisomal fatty acid beta oxidation that results in the accumulation of very long fatty acids in tissues
Describe cerebral adrenoleukodystrophy (ALD)
Progressive demyelination leading to vegetative state and death
What organelle is mitochondrial myopathy due to?
Mitochondria
Describe mitochondrial myopathy
Muscles exhibit “ragged red” fibers that contain accumulations of glycogen and neutral lipids
Symptoms: low energy, free radical production and lactic acidosis that result in muscle weakness, exercise intolerance, trouble with balance and coordination and seizures
What organelle is albinism due to?
Cytoplasmic inclusions: Melanosomes
Describe albinism
Lack of tyrokinase activity preventing melanin synthesis (pink eyes because reflect blood from back of iris)
What organelle is Von Gierke disease due to?
Cytoplasmic inclusions: Glycogen
Describe Von Gierke disease
Impaired breakdown of glycogen causes an enlargement of the liver
What is another name for Von Gierke disease
Type 1 glycogen storage disease
What organelle are lipid storage disease due to?
Cytoplasmic inclusions: lipids
Describe lipid storage diseases
Inherited metabolic disorders where harmful amounts of lipids accumulate in cells and tissues which can cause permanent damage especially in the brain, PNS, liver, spleen, and bone marrow
What is another name for the lipid storage diseases
Lipidoses
What organelle is nemaline rod myopathy due to?
Cytoskeleton: microfilaments
Describe nemaline rod myopathy
Congenital neuromuscular disorder that causes muscle weakness and results from mutations in the ACT1 gene which codes for alpha-actin
You can find rod-like inclusions (nemaline bodies) in the sarcoplasm of skeletal muscle fibers
What organelle is ciliary dyskinesia due to?
Cytoskeleton: microtubules
Describe the 4 types of ciliary dyskinesias
- Absent inner dynein arms
- Radial spoke defect
- Absent central pair
- Absent inner and outer dynein arms
What do ciliary dyskinesias predisposes patients for? More common in what type of pts?
Ineffective ciliary mvt impairs mucociliary clearance: recurrent chest infections and these are more common in smokers
What organelle is epidermolysis bullosa simplex due to?
Cytoskeleton: intermediate filaments
Describe epidermolysis bullosa simplex
Increasing blistering related to friction (shoes/socks) resulting from an autosomal dominantly inherited defect in keratins 5 and 14
What cell junction is celiac disease due to?
Zonula occludens
Describe celiac disease
Damages the lining of the small intestine and prevents it from absorbing parts
of food that are important for staying healthy. Can be caused by Zonulin, a zonula occludens toxin
secreted by the pathogen Vibrio cholera. Zonulin breaks down tight junctions, increasing their
permeability between cells of the wall of the digestive tract.
What cell junction is bacteriodes fragilis due to?
Zonula adherens
Describe bacteriodes fragilis
Bacterium produces a toxin (B. fragilis enterotoxin) that alters zonula
adherens function, so compounds leak between cells. Associated with diarrheal diseases.
What cell junction is arrhythmogenic right ventricular cardiomyopathy/dysplasia due to?
Desmosomes
Describe arrhythmogenic right ventricular cardiomyopathy/dysplasia
Heart muscle disease
characterized by life-threatening arrhythmias and increased risk of sudden heart failure. Caused by
mutations in genes encoding desmosomal proteins.
What cell junction is Charcot-Marie-Tooth X disease (CMTX) due to?
Gap junctions
Describe Charcot-Marie-Tooth X disease (CMTX)
Point mutation in the connexin-32 gene
on the X-chromosome. The connexin-32 protein is expressed in Schwann cells that wrap around
nerve axons, so CMTX affects components of the nervous system, which in turn affects muscle
function. A typical feature includes weakness of the foot and lower leg muscles. Foot deformities,
such as high arches, are common due to weakness of the small muscles in the feet.
