Muscular Dystrophies

Question 1

Duchene is what type of genetic disorder?

Answer 1

X recessive disorder

Question 2

Duchenne disorder is a disorder typically due to ________ mutation which leads to an _________

Answer 2

Frameshift mutation, early stop codon

Question 3

The gene involved is the _________ gene and it is ___________

Answer 3

Dystrophin, truncated or absent

Question 4

DMD is the __________ protein coding human gene, which leads to ____________ of spontaneous mutations

Answer 4

Largest, increased chances

Question 5

Dystrophin is the anchor btw ____________ and __________ which is connected to _________in _______ fibres, primarly _________ and ____________

Answer 5

Dystroglycan A and B, Actin, ECM, muscle, skeletal and cardiac muscles

Question 6

Due to loss of dystrophin, the ________ are released into blood and this leads to ________

Answer 6

Enzymes, myonecrosis

Question 7

Which biochemical testing is involved in Duchene?

Answer 7

CK increased and aldolase also. AST and ALT

Question 8

Which genetic testing confirms Duchenne?

Answer 8

PCR, and western blot

Question 9

What is the onset of the disease? Duchenne

Answer 9

5 years

Question 10

Which is the most common cause of death in Duchenne patients?

Answer 10

Dilated cardiomyopathy

Question 11

Weakness begins in the _____________ muscles. There is ___________ of the calf due to ________. Child has to ___________ to stand. He has a ________ gait. There is ________ atrophy and ________

Answer 11

Pelvic girdle muscles, pseudohypertrophy due to fibrofatty replacement of muscle, pushes on legs to stand, thigh and lordosis

Question 12

Which sign is seen in Duchenne

Answer 12

Gowers: patient uses upper extremities to help stand up

Question 13

The gower sign is classically seen in Duchenne muscular dystrophy, but also in other ______________ and ___________

Answer 13

Muscular dystrophies and inflammatory myopathies such as polymyositis

Question 14

Which type of genetic disorder is Becker muscular dystrophy?

Answer 14

X linked recessive

Question 15

Becker dystrophy is typically due to _________ which leads to loss of ________………

Answer 15

Non frame shift mutation, loss of functional instead of truncated

Question 16

Which disorder is more severe, Duchenne or Becker?

Answer 16

Becker is less severe

Question 17

In Becker, the carrier females have less severe form, so __________

Answer 17

More males give gene to female offspring

Question 18

In Becker dystrophy, the patient often lives up to?

Answer 18

30 years

Question 19

Deletions can cause both _________

Answer 19

Duchenne and Becker dystrophies. 2/3 of cases have large deletions spanning one or more exons

Question 20

In Myotonic type 1, what kind of genetic disorder is this?

Answer 20

Autosomal dominant

Question 21

There ___________ in the _________ gene in Myotonic dystrophy

Answer 21

Trinucleotide repeat expansion, DMPK

Question 22

There is __________ bonding between C and G nucleotides. This leads the RNA to form ________

Answer 22

Increased hydrogen, condensed clumps

Question 23

Due to the expansion of the DMPK gene, there is abnormal expression of _______ in Beckers dystrophy

Answer 23

Myotonin protein kinase

Question 24

What are the symptoms of Beckers dystrophy

Answer 24

CTG

cataracts, toupee (early balding in men) gonadal atrophy, myotonia, muscle wasting, arrythmia

Can grip some ones hand, but cannot relax, just contracted there

Question 25

Which type of disorder is Rett syndrome?

Answer 25

Sporadic disorder

Question 26

Which gender is Rett syndrome typically seen in?

Answer 26

Girls (boys die in utero or shortly after birth)

Question 27

What type of mutation happens in Rett Syndrome?

Answer 27

Mutation of the MECP2 on X chromosome

Question 28

What are the symptoms of the Rett syndrome?

Answer 28

Regression in motor, verbal and cognitive abilities, ataxia, aphasia, seizures

Stereotypical hand wringing