Inherited Diseases of Skeletal Muscle

Question 1

When will Muscular Dystrophies present?

Answer 1

Near Adulthood

– NOT IN INFANCY

Question 2

Muscular Dystrophies involve progressive muscle damage near adulthood. They will NOT present when?

Answer 2

NOT present in infancy

Question 3

What are 2 X-linked Muscular Dystrophies?

Answer 3

1. Duchenne

2. Becker

Question 4

What gene is mutation and where with X-linked Muscular Dystrophies?

Answer 4

DMD gene – Xp21 chromosome

Question 5

What protein is absent or decreased with X-linked Muscular Dystrophies?

Answer 5

Dystrophin

Question 6

Can female carries of X-linked muscular dystrophies be affected?

Answer 6

May be mildly symptomatic

Question 7

Level of Dystrophin protein with Duchenne Muscular Dystrophy?

Answer 7

ABSENT

Question 8

When will symptoms present with Duchenne muscular dystrophy and what is the outlook?

Answer 8

Symptoms around 5 yo

– Death at 25-30 yo

Question 9

What are the symptoms of Duchenne?

Answer 9

Muscle weakness and clumsiness

Question 10

Besides muscles, what other impairments will be seen with Duchenne?

Answer 10

Heart and cognitive impairments

– Dystrophin protein is absent from heart and CNS too

Question 11

Level of Dystrophin protein with Becker muscular dystrophy?

Answer 11

DECRASED

Question 12

When will symptoms present and what is the outlook for Becker muscular dystrophy?

Answer 12

Symptoms at late childhood

– NORMAL LIFE SPAN

Question 13

Does Becker muscular dystrophy also have cardiac disease like Duchenne?

Answer 13

Yes

Question 14

What histo change of the muscles will be present with Duchenne and Becker x-linked muscular dystrophies?

Answer 14

Pseudohypertrophy

=> increased collagen and fat

Question 15

What histo change of the muscles will be present with Duchenne and Becker Muscular Dystrophies?

Answer 15

Pseudohypertophy

=> increased collagen and fat

Question 16

What are the 2 X-linked Muscular Dystrophies, what gene and protein are mutated/absent/decreased?

Answer 16

** DMD gene on Xp21 mutated
Duchenne - ABSENT Dystrophin
Becker - DECREASED Dystrophin

Question 17

Limb-Girdle Muscular Dystrophy has forms that are inherited how?

Answer 17

AD and AR forms

Question 18

What is the symptom of Limb-Girdle Muscular Dystrophy?

Answer 18

Proximal muscle weakness

Question 19

How is Myotonic Dystrophy inherited?

Answer 19

AD

Question 20

What trinucleotide repeat is seen with Myotonic Dystrophy?

Answer 20

CTG repeats

Question 21

What protein/gene is mutated with Myotonic Dystrophy?

Answer 21

DMPK

Question 22

What histo change will be present with Myotonic Dystrophy?

Answer 22

Ring fiber

Question 23

What are the general symptoms (4) of Myotonic Dystrophy?

Answer 23

Weakness
Cataracts
Endocrinopathy
Cardiomyopathy

Question 24

What are the general symptoms (4) with Myotonic Dystrophy?

Answer 24

Weakness
Cataracts
Endocrinopathy
Cardiomyopathy

Question 25

What specific muscle weakness symptom will present with Myotonic Dystrophy?

Answer 25

Stiffness -- difficulty releasing grip

Question 26

Ptosis and "hatchet face" can present with?

Answer 26

Myotonic Dystrophy

Question 27

Diseases of lipid or glycogen metabolism can also cause myopathies. What are 3?

Answer 27

Carnitine Polmitoyltransferase 2 deficiency McArdle Disease Pompe Disease

Question 28

Symptoms of Carnitine Palmitoyltransferase 2 deficiency?

Answer 28

Episodic muscle damage with exercise and fasting

Question 29

McArdle Diseases involves _____ deficiency

Answer 29

Myophosphorylase deficiency

Question 30

Symptoms of McArdle Disease?

Answer 30

Episodic muscle damage with exercise

Question 31

Pompe Disease involves _____ deficiency

Answer 31

Acid Maltase deficiency

Question 32

Symptoms of Pompe Disease?

Answer 32

Glycogenesis of infancy

Question 33

How is mitochondrial DNA inherited?

Answer 33

Maternal inheritance

Question 34

With Mitochondrial Myopathies, what is impaired?

Answer 34

Ability to generate ATP is impaired

Question 35

What histo change will be seen with Mitochondrial Myopathies?

Answer 35

Ragged Red Fibers

Question 36

What are the general symptoms of Mitochondrial Myopathies?

Answer 36

Weakness, Rhabdomyolysis (increased creatine Kinase)

Question 37

What will be increased in the serum with Mitochondrial myopathies?

Answer 37

Serum Creatine Kinase

Question 38

What specific weakness is seen with Mitochondrial myopathies?

Answer 38

EOM weakness | = Chronic progressive External Ophthalmoplegia