Charcot Marie Tooth

Question 1

Common features

Answer 1

develops in early adulthood, progressive difficulty with movement, muscle weakness in feet and/or hands, high arched feet, depressed tendon reflexes, abnormal gait, curled toes, muscle atrophy, sensorineural hearing loss, numbness

Question 2

Most common gene

Answer 2

PMP22 on chromosome 12

Question 3

Most common mode of inheritance

Answer 3

AD

Question 4

CMT 1 subtype

Answer 4

most common, defects in myelin sheath, slow degradation of sheath, AD

Question 5

CMT 2 subtype

Answer 5

less common and less severe than CMT1, defect in axon, AD

Question 6

CMT3 subtype

Answer 6

AKA dejerine-sottas syndrome, rare and severe, affects myelin sheath, severe muscles weakness and sensory issues, early childhood onset, AR

Question 7

CMT4 subtype

Answer 7

rare and severe, affects myelin sheath, lose ability to walk, early childhood onset, AR

Question 8

CMT X subtype

Answer 8

axonopathy associated with myelin changes in the second stage, X-linked

Question 9

Testing options

Answer 9

1. Del/dup of PMP22 - catches 50% of cases
2. Multigene panel of most common genes
3. Exome sequencing
4. CMA