Limb Girdle Muscular Dystrophy

Question 1

Clinical features

Answer 1

progressive skeletal muscle weakness in shoulders and hips, muscle wasting, weakened hip and leg muscles causing a waddling gait, dysphagia, arrhythmias, cardiomyopathy, conduction abnormalities, chewing/swallowing problems, contractures, dysarthria, hypertrophy, lordosis, DD, ID

Question 2

Prognosis

Answer 2

typically wheelchair bound in 20s or 30s, heart muscle weakness and abnormal electrical activity can increase risk of sudden death. Most live into adulthood but do not reach their full life expectancy

Question 3

Limb-girdle muscular dystrophy type 1

Answer 3

AD, accounts for approx 10% of cases

Question 4

Limb-girdle muscular dystrophy type 2

Answer 4

AR, accounts for approx 90% of cases, generally show symptoms earlier in life and are associated with moderate to severe muscle weakness

Question 5

Calpainopathy (LGMD type 2A) - frequency

Answer 5

Type 2A is the most common form of LGMD, accounting for 30% of cases.

Question 6

LGMD type 2A - gene and inheritance

Answer 6

CAPN3 gene & AR

Question 7

LGMD type 2A symptoms

Answer 7

symmetric and progressive weakness of proximal limb-girdle muscles, symmetric muscle atrophy of the proximal limb and trunk muscles, scapular winging, scoliosis, joint contractures

Question 8

Age of onset for LGMD type 2A

Answer 8

ranges from 2yo to 40 yo

Question 9

First clinical signs of LGMD type 2A

Answer 9

tendency to walk on tiptoe, difficulty running, scapular winging

Question 10

Dysferlinopathy (limb-girdle muscular dystrophy type 2b) - frequency

Answer 10

second most common type

Question 11

Dysferlinopathy (LGMD type 2b) - gene & inheritance

Answer 11

DYSF gene & AR

Question 12

Dysferlinopathy (LGMD type 2b) symptoms

Answer 12

early weakness and atrophy of the pelvic and shoulder girdle muscles in adolescence or young adulthood, onset in the proximal lower-limb musculature in late teens or later, slow progression, massive elevation of serum CK concentration

Question 13

Limb girdle muscular dystrophy type 1B - frequency

Answer 13

about 10% of people with LGMD have subtype 1b

Question 14

Limb girdle muscular dystrophy type 1B - gene & inheritance

Answer 14

LMNA gene & AD

Question 15

Limb girdle muscular dystrophy type 1B - onset

Answer 15

adolescence to late adulthood

Question 16

LGMD type 1B - symptoms

Answer 16

milder muscle weakness in legs, muscle weakness typically affects proximal muscles in upper legs

Question 17

Diagnosis of LGMD

Answer 17

CK level (elevated), electromyography, muscle biopsy, genetic testing)

Question 18

Genetic testing for LGMD

Answer 18

Multigene panels

Question 19

Management

Answer 19

No cure or treatment, management should be from multiple specialists