Neuromuscular Disorders

Question 0

What is the genetic mutation in MELAS (mitochondrial encephalomyelopathy, lactic acid ptosis and stroke like episodes)

Answer 0

An A3243G mutation of mtDNA common clinical features include small stature, proximal muscle weakness , easy fatigability, myalgias with excercise and NIDDM

Question 1

What antibodies can be seen in Lambert Eaton syndrome

Answer 1

P/Q type calcium channel and N type calcium channel

Question 2

Duplication of the PMP22 gene is associated with

Answer 2

CMT1 which is associated with conduction slowing absent sensory responses and low amplitude motor responses on EMG

Question 3

Deletion of PMP22 gene is associated with

Answer 3

HNPP

Question 4

What gene is affected in familial amyloidosis

Answer 4

Point mutation in TTR(transthyretin gene)

Question 5

What is the genetic mutation in CMT2A

Answer 5

Mutations in the MFN2 (mitofusin 2) gene

Question 6

CMTX is associated with what genetic mutation

Answer 6

Point mutation in GJB1 (connexin 32) gene

Question 7

What muscles are involved and posterior interosseous neuropathy

Answer 7

Abductor pollicis longus, extensor individual and extensor carpi ulnaris

Question 8

What antibodies are associated with stiff person syndrome

Answer 8

Amphiphysin antibodies these antibodies can also be seen in Paraneoplastic encephalomyelitis

Question 9

What genetic abnormalities are seen and myotonic dystrophy type one

Answer 9

CTG trinucleotide expansion in the untranslated region of the DMPK gene. Clinical presentation includes frequent falls, excessive daytime sleepiness ptosis and facial weakness without ophthalmoplegia. Delayed muscle relaxation after hand grip and bow tie sign with percussion of the tongue weakness is more pronounced in the distal musculature rather than proximal musculature

Question 10

What is the genetic defect in myotonic dystrophy type 2

Answer 10

Zinc finger protein 9 gene

Question 11

What is the genetic mutation and para myotonia congenita

Answer 11

Mutations in the SCNA4 gene which encodes the alpha subunit of the muscle sodium channel myotonia typically becomes more pronounced with repeated muscle contractions

Question 12

What are the genetic mutations and myotonia congenita

Answer 12

CLCN1 which encodes a chloride channel associated with the warm-up phenomenon of improvement and stiffness with repeated use

Question 13

What three disorders can be caused by mutations in the SCN4A gene which codes for the alpha subunit of the muscle sodium channel

Answer 13

Hyperkslemic periodic paralysis, hypo Hypokalemic periodic paralysis and para myotonia congenita