Skeletal muscle diseases

Question 1

Autoantibodies against the post-synaptic ACH receptors

Answer 1

Myasthenia gravis

Question 2

Antibody against muscle specific receptor tyrosine kinase

Answer 2

Myasthenia gravis

Question 3

Tension test

Answer 3

Administration of acetylcholinesterase inhibitor that can lead to rapid improvement in myasthenia gravis

Question 4

Treatment for myasthenia gravis

Answer 4

Pyridostigmine - acetylcholinesterase inhibitor

Immunosuppressants

Question 5

Antibodies block ACH release by inhibiting a presynaptic Ca channel

Answer 5

Lambert-Eaton myasthenic syndrome

Question 6

Autoimmune diseases associated with Lambert-Eaton myasthenic syndrome

Answer 6

Vitiligo and thyroid diseases

Question 7

Disorder of skeletal muscle caused by disruption of muscle innervation

Answer 7

Neurogenic injury

Question 8

Result of direct damage to myofibers

Answer 8

Myopathic injury

Question 9

Autoantibodies associated with interstitial lung disease, nonerosive arthritis, and Mechanic’s hand skin rash in dermatomyositis

Answer 9

Anti-jo-1/Histidyl tRNA synthetase

Question 10

Autoantibodies associated with paraneoplastic and juvenile cases of dermatomyositis

Answer 10

Anti-p155/p140 –> transcriptional regulators

Question 11

Autoantibodies associated with Gottron papules and heliotrope rash in dermatomyositis

Answer 11

Anti-Mi2 –> helicase

Question 12

Immunohistochemistry in dermatomyositis

Answer 12

CD4+ rich infiltrate
Deposition of C5b-C9 in capillary vessels

Question 13

Malignancies associated with dermatomyositis

Answer 13

Lung, stomach, and ovary

Question 14

Skeletal muscle injury mediated by CD8+ T cells

Answer 14

Polymyositis

Question 15

Deletions or frameshift mutations that result in a total absence of dystrophin

Answer 15

Duchenne muscular dystrophy

Question 16

Synthesis of a truncated version of dystrophin which retains partial function

Answer 16

Becker muscular dystrophy

Question 17

Inheritance of myotonic dystrophy

Answer 17

Autosomal dominant

Question 18

Multisystem disorder associated with muscle weakness, cataracts, endocrinopathy, and cardiomyopathy

Answer 18

Myotonic dystrophy

Question 19

Expansions of CTG triplet repeats in 3’ noncoding region of the DMPK gene

Answer 19

Myotonic dystrophy

Question 20

Inheritance of ion channel myopathies

Answer 20

Autosomal dominant

Question 21

Most common mutation in MELAS

Answer 21

gene encoding mitochondrial tRNA-leucine (MTTL1)

Question 22

Increased creatine kinase and increased ESR

Answer 22

Inflammatory myopathies

Question 23

Increased creatine kinase and normal ESR

Answer 23

Statin induced myopathy
Hypothyroid myopathy

Question 24

Normal creatine kinase and ESR

Answer 24

Glucocorticoid induced myopathy

Question 25

Normal creatine kinase and increased ESR

Answer 25

Polymyalgia rheumatica