Dystrophinopath ies

Question 1

Types Albinism

Answer 1

Ocular Albinism:
• Affects only the eyes,
Not the skin or hair.
• Inherited as X-linked disorder
• Mostly in boys
Oculocutaneous Albinism:
• Affects the eyes, hair and skin
• Inherited as autosomal recessive
• Include several forms
• The first form (OCA 1) involves the
tyrosinase enzyme which converts tyrosine
into melanin

Question 2

Eve abnormalities
Albinism

Answer 2

nystagmus, Photophobia, poor
vision, strabismus, transiucent iris

Question 3

Dystrophinopathies
Types and gene

Answer 3

• Duchenne muscular dystrophy
Becker muscular dystrophy
a spectrum of X-linked muscle disease

Question 4

Dystrophin Gene

Answer 4

Locus
Хр21)
X-Linked
79 exons

Question 5

• The most common mutation are
Dystrophin

Answer 5

The most common mutation are deletions in
65-70%
• Duplications in 7%
Point mutations or small deletions/insertions
in the remainder

Question 6

Dystrophin
Localized on the

Answer 6

• localized on the intracellular surface of
the sarcolemma along all the lenath of
the myofibers •

Question 7

Dystrophin It assembles with the……….
For……

Answer 7

dystrophin- associated glycoprotein complex (DGC)

•Stabilizes the fibers during contractions
by to actin B-dystroglycan

Question 8

Duchenne Muscular Dystrophv

Answer 8

Most severe type
Wasting muscles
• Incidence: males at a rate of 1 in
3,500 births
• The mean age of diagnosis is - 4
years (range: 16 months - 8 years)
• Progressive symmetric muscle weakness (proximal > distal)

Question 9

Becker Muscular Dystrophy

Answer 9

Milder form
• male births
• Presents later than DMD, between ages /5 and 15 years
• Severity varies among patients
• Wheelchair dependency (after age 16 years)

Question 10

Clinical Features
Dystrophinopathies
Duchenne

Answer 10

• Gross motor delay - mean age of walking is
  approximately 18 months → vegios 12 moths
• Gait abnormalities - persistent toe walking, waddling gait
• Difficulty rising from the ground
  -Difficulty climbing stairs running, jumpina
  -Frequent falls
  -Calf muscles: hypertrophic and firm to palpation
• Increase in serum CK (creatine phosphokinase) - - -Wheelchair bound by age 12 years
• Learning difficulties in 5% of patients
• Speech problems in 3% of patients
  -Cardiomyopathy at 14 to 18 years
  -Few patients live beyond 30 years of
  age
• Reparatory problems and
• cardiomyopathy leading to congestive
  heart failure are the usual cause of
  death

Question 11

Diagnosis
Dystrophy

Answer 11

–Serum CK very high
- Serum alanine transaminase and aspartate transaminase levels
-Genetic Testing
-Muscle biopsy

Question 12

Managemen
Muscular dystrophy, Cardiomyopathy ,Scoliosis:

Answer 12

Cardiomyopathy:
•ACEinhibitor and/or beta
blocker
• diuretics and digoxin are
used as needed
Scoliosis:
bracing
surgery
Muscular dystrophy:
• Corticosteroid:
Prednisone
Deflazacourt
• improve the muscle strength and function
•NOT recommended in children before age two years