Organelle Diseases

Question 1

What organelle is progeria due to?

Answer 1

Nuclear envelop

Question 2

What organelle is dyskeratosis congenita due to?

Answer 2

Ribosome

Question 3

Describe dyskeratosis congenita

Answer 3

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

Question 4

Describe progeria

Answer 4

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)

Question 5

What organelle is cystic fibrosis due to?

Answer 5

ER

Question 6

Describe cystic fibrosis

Answer 6

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

Question 7

What organelle is congenital disorder of glycosylation syndrome due to?

Answer 7

Golgi

Question 8

What was congenital disorder of glycosylation syndrome previously called?

Answer 8

Carbohydrate-deficient glycoprotein syndrome

Question 9

Describe congenital disorder of glycosylation syndrome

Answer 9

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

Question 10

What are lysosomal storage diseases?

Answer 10

50+ rare metabolic inherited diseases resulting from defects in lysosomal function

Question 11

What organelle is peroxisomal disease due to?

Answer 11

Peroxisome

Question 12

Describe peroxisomal disease

Answer 12

Neurological diseases that results from defects in biogenesis of peroxisomes or in enzymes in them

Question 13

What organelle is adrenoleukodystrophy (ALD) due to?

Answer 13

Peroxisome

Question 14

Describe adrenoleukodystrophy (ALD)

Answer 14

Disorder of peroxisomal fatty acid beta oxidation that results in the accumulation of very long fatty acids in tissues

Question 15

Describe cerebral adrenoleukodystrophy (ALD)

Answer 15

Progressive demyelination leading to vegetative state and death

Question 16

What organelle is mitochondrial myopathy due to?

Answer 16

Mitochondria

Question 17

Describe mitochondrial myopathy

Answer 17

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

Question 18

What organelle is albinism due to?

Answer 18

Cytoplasmic inclusions: Melanosomes

Question 19

Describe albinism

Answer 19

Lack of tyrokinase activity preventing melanin synthesis (pink eyes because reflect blood from back of iris)

Question 20

What organelle is Von Gierke disease due to?

Answer 20

Cytoplasmic inclusions: Glycogen

Question 21

Describe Von Gierke disease

Answer 21

Impaired breakdown of glycogen causes an enlargement of the liver

Question 22

What is another name for Von Gierke disease

Answer 22

Type 1 glycogen storage disease

Question 23

What organelle are lipid storage disease due to?

Answer 23

Cytoplasmic inclusions: lipids

Question 24

Describe lipid storage diseases

Answer 24

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

Question 25

What is another name for the lipid storage diseases

Answer 25

Lipidoses

Question 26

What organelle is nemaline rod myopathy due to?

Answer 26

Cytoskeleton: microfilaments

Question 27

Describe nemaline rod myopathy

Answer 27

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

Question 28

What organelle is ciliary dyskinesia due to?

Answer 28

Cytoskeleton: microtubules

Question 29

Describe the 4 types of ciliary dyskinesias

Answer 29

1. Absent inner dynein arms 2. Radial spoke defect 3. Absent central pair 4. Absent inner and outer dynein arms

Question 30

What do ciliary dyskinesias predisposes patients for? More common in what type of pts?

Answer 30

Ineffective ciliary mvt impairs mucociliary clearance: recurrent chest infections and these are more common in smokers

Question 31

What organelle is epidermolysis bullosa simplex due to?

Answer 31

Cytoskeleton: intermediate filaments

Question 32

Describe epidermolysis bullosa simplex

Answer 32

Increasing blistering related to friction (shoes/socks) resulting from an autosomal dominantly inherited defect in keratins 5 and 14

Question 33

What cell junction is celiac disease due to?

Answer 33

Zonula occludens

Question 34

Describe celiac disease

Answer 34

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.

Question 35

What cell junction is bacteriodes fragilis due to?

Answer 35

Zonula adherens

Question 36

Describe bacteriodes fragilis

Answer 36

Bacterium produces a toxin (B. fragilis enterotoxin) that alters zonula adherens function, so compounds leak between cells. Associated with diarrheal diseases.

Question 37

What cell junction is arrhythmogenic right ventricular cardiomyopathy/dysplasia due to?

Answer 37

Desmosomes

Question 38

Describe arrhythmogenic right ventricular cardiomyopathy/dysplasia

Answer 38

Heart muscle disease characterized by life-threatening arrhythmias and increased risk of sudden heart failure. Caused by mutations in genes encoding desmosomal proteins.

Question 39

What cell junction is Charcot-Marie-Tooth X disease (CMTX) due to?

Answer 39

Gap junctions

Question 40

Describe Charcot-Marie-Tooth X disease (CMTX)

Answer 40

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.