Muscular dystrophy vignette

Question 1

HCM majority of mutations

Answer 1

missense in structural genes

Question 2

cardiomyocyte and cardiac hypertrophy phenotype

Answer 2

organ hypertrophy

Question 3

myocyte disrray pheno

Answer 3

function compromised

Question 4

interstitial and replacement fibrosis pheno

Answer 4

propensity to arrhythmia

Question 5

dysplastic intramyocardial arterioles pheno

Answer 5

ischemia

Question 6

HCM clinical presentations

Answer 6

• cardiac murmur (if LV outflow obstruction)
• cardiac “pump” failure (dyspnea, angina)
• arrhythmia (syncope/sudden death)
• sports/family screening

Question 7

dx for HCM

Answer 7

-ECHO, EKG, MRI, FHx, genetic testing, CXR

Question 8

myostatin and skeletal muscle growth: _______ length and _______ growth

Answer 8

• increase (recruit myoblasts)

- increase (recruit myoblasts and increase size and number of myofibrils)

Question 9

Myostain: muscle growth regulator (inhibitor) - normally made and secreted by muscles as a _______ for muscle growth

Answer 9

negative feedback

Question 10

Malignant hyperthermia mytation

Answer 10

RYR1

Question 11

malignant hyperthermia pheno

Answer 11

hypermetabolism, skeletal muscle damage, hyperthermia

DEATH if untreated

Question 12

what to treat malignant hyperthermia with

Answer 12

Dantrolene

Question 13

What anesthesia can cause MH

Answer 13

Halothane and succinylcholine

Question 14

increased Ca2+ from the SR result in increased _______ consumption and anaerobic metabolism and cause the muscle rigidity

Answer 14

oxygen

Question 15

calcium transport from the SR into the sarcoplasm is mediated by the ________ receptor

Answer 15

ryanodine receptor, isoform 1 (RYR1)

Question 16

abnormal skeletal muscle RYR1 or an associated structure that allows abnormal Ca2+ release when exposed to an

Answer 16

anesthetic triggering agent

Question 17

_______, the tx for MF, is known to inhibit _______ via _______

Answer 17

• Dantrolene sodium
• calcium
• RYR1 antagonism

Question 18

MH rxn caused by

Answer 18

an altered Ca2+ balance between the lumen of the SR and the sarcoplasm

Question 19

in MH, accumulation of calcium in the sarcoplasm causes ________

Answer 19

uncontrolled anaerobic and aerobic metabolism and sustained muscle cell contraction

Question 20

ATP depletion eventually causes

Answer 20

widespread muscle fiber hypoxia