Muscle Diseases

Question 1

Gross motor delay, weakness, delay in walking

Answer 1

DMD

Question 2

Often dominant inheritance,
progressive weakness,
CK is

Answer 2

Dystrophy due to abnormal nuclear function, organization or transcription
Ex: FSHD

Question 3

Myopathies usually have __________ muscle weakness

Answer 3

diffuse or proximal

Question 4

weakness starts in teens, early adulthood, commonly ASYMMETRIC, bilateral facial weakness (eyes), scapular winging, near normal CK, other organ system involvement

Answer 4

Facioscapulohumeral muscular dystrophy (FSHD)

Question 5

If DTR are increased, then…

Answer 5

neuromuscular problem is in brain/spinal cord

Question 6

inherited in any pattern, Diffuse weakness in infancy/prenatally, all muscles affected including extra-ocular, normal CK, stable or slowly progressive course

Answer 6

Congenital myopathies

Question 7

Hypotonia, diffuse weakness, contractures, opthalmoplegia, scoliosis, resp insufficiency, normal cognition, rare cardiomyopathy

Answer 7

Congenital myopathies

Question 8

If tone is increased, then…

Answer 8

neuromuscular problem is in brain/spinal cord

Question 9

Dystrophies of nuclear transcription, nuclear membrane have _______ CK

Answer 9

near-normal CK

Question 10

FSHD is _________ inheritance

Answer 10

Autosomal dominant

Question 11

Most disorders of contractile mechanism

Answer 11

Congenital myopathies

Question 12

Inherited disorders characterized by progressive degeneration/regeneration

Answer 12

Muscular dystrophies

mismatch between injury/repair

Question 13

Late onset signs of DMD

Answer 13

Speech delay, articulation problems, cognitive delay

Question 14

X-linked muscular dystrophies

Answer 14

Duchenne, Becker

Question 15

Transcription of DUX4

Answer 15

FSHD

Question 16

Allelic to DMD

Answer 16

BMD (same gene involved)

Question 17

Deletion within 4q35, decreased methylation of D4Z4, transcription of DUX4

Answer 17

FSHD1

Question 18

Elevated CK indicates

Answer 18

Membrane stability/repair dysfunction

Question 19

Usually recessive or x-linked, Progressive proximal to distal weakness, loss of muscle with fibrosis and fat replacement, CK >5x normal

Answer 19

Dystrophy due to membrane defect

Ex: Duchenne muscular dystrophy

Question 20

Weakness around age 3, progressive to wheelchair around age 12, calf hypertrophy

Answer 20

DMD

Question 21

SMCHD1 mutation in 18p11.32 gene responsible for methylation of D4Z4 long repeat, transcription of DUX4

Answer 21

FSHD2

Question 22

weakness in childhood, cardiomyopathy, muscle fatigue/cramping

Answer 22

BMD

Question 23

Core myopathies associated with genes

Answer 23

RYR1, SEPN1

Question 24

What gene is associated with all types of congenital myopathies?

Answer 24

RYR1 - Ryanodine receptor - release of calcium to initiate contraction

Gene mutation also risk for malignant hyperthermia

Question 25

Dystrophin mutations

Answer 25

Large deletions, duplications

Point mutation