Cardiomyopathy genetics

Question 1

Hypertrophic Cardiomyopathy

Answer 1

disease of sarcomere

1) B-MyHC
2) cTNT
3) cMyBP-C (cardiac myosin binding protein)

leads to sudden cardiac death in athletes

Question 2

Dilated cardiomyopathy

Answer 2

disease of cardiac cytoskeleton (decreases contractility)

L ventricle chamber enlargement

Question 3

Glycogen cardiomyopathy

Answer 3

accumulation of glycogen in lysosome

1) Pompes (1,4-glucosidase)
2) Fabry’s (galactosidase A)
3) Danons (LAMP2)

Question 4

Restrictive Cardiomyopathy

Answer 4

walls rigid, bilateral enlargement

Troponin I (TNNT 13) deficient

Question 5

Arythmogenic R ventric (ARVC)

Answer 5

myocytes replaced with fibrofatty tissue

Disease of Desmosomes

Question 6

Long QT (LQTS)

Answer 6

loss of function K+ channels
increase inward Na+ channels

repolarization disorder

Complications: Torsades de Pointes, syncopal episode

Treatment = b-blocker

Question 7

Short QT (SQTS)

Answer 7

Gain of function in K+ channels –> K+ moves out faster than it should

Question 8

Brugada Syndrome

Answer 8

ST segment elevation in V1-V3

Common in E/SE Asia

Loss of Function = SCN5A = Na+ channel…unopposed transient K+ outflow

before heart totally depolarizes it repolarizes

Question 9

Cardiac conduction disease and sinus node dysfunction

Answer 9

causes sick sinus syndrome

mutation in Na+ channel

Question 10

Catecholaminergic polymorphic ventricular tachy (CPVT)

Answer 10

too much ca2+ from SR or leaks into cell

mutation in RyR2 + calsequestrin

prolonged sarcomere contraction