Miscellaneous Flashcards
What is myasthenia gravis caused by?
- Autoimmune disease: antibodies block nAChRs at neuromuscular junctions.
- Prevents nerve impulses from triggering muscle contractions.
What are the symptoms of myasthenia gravis?
Skeletal muscle weakness, esp of eyes, face and swallowing.
How is myasthenia gravis treated?
- Acetylcholinesterase inhibitors
- Thymectomy
What is the result of faulty peroxisome protein targeting?
Peroxisome biogenesis disorders, e.g.
- Zellweger syndrome
- Rhizomelic chondrodysplasia punctate
What is Zellweger syndrome?
Mutation in any of 12 PEX genes (inc. Pex5)… no PO protein targeting… VLCFA accumulation… neurone development impairment.
What is Rhizomelic chondrodysplasia punctate?
Mutation of Pex7 leads to skeletal abnormalities.
Name and describe a disease associated with lysosomal protein targeting deficiency.
- I cell disease
- deficiency in kinase which phosphorylates mannose residues on proteins destined to lysosomes
Why does vitamin D deficiency cause osteomalacia?
- Vitamin D required for calcium reabsorption in small intestine.
- No vitD… no calcium hydroxyapatite to mineralise bone.
Why would cellulitis cause oedema?
Cellulitis = inflammation of dermis so increased inflammatory cells and proteins in interstitium - increased interstitial oncotic pressure.
What are the 2 types of Huntington’s disease?
Normal age of onset (30-50yrs) and juvenile HTT (<20yrs)
When is Juvenile Huntington’s more likely to occur?
When condition inherited from father
What are the symptoms of Huntington’s?
Seizures
Abnormal gait
Personality change
Dementia
Which gene is involved in Huntington’s and what protein does it encode?
HTT gene on chromosome 4. Encodes huntingtin protein.
What is the normal structure of HTT gene?
Short tandem repeat region of 10-35 CAG trinucleotide repeats
What mutation causes Huntington’s?
Expansion of CAG repeats . 37-80 repeats
