DMD Flashcards
onset
2-6 years
symptoms (3)
generalised weakness, trunk and limb muscle wasting first, calves hypertrophy
disease affects all
voluntary muscles
disease progression speed
slow
when is survival rare
beyond 20
inheritance is
x linked recessive
who are carriers
females
what is the most common inherited childhood lethal disoder
DMD
how many newborn males affected
1 in 3500-6000
how many cases are from new mutations
1 in 3 cases
diagnostic factors (2)
proximal lower girdle weakness and elevated creatinine kinase levels
CK
creatinine kinase
what do parents often report (3)
developmental delay, difficulty with stairs, frequent falls
at what age are they wheel chair dependent
7-13
what other muscles are affected (2)
cardiac and smooth muscle
what happens at age 20 if not on mechanical ventilation
cardiorespiratory failure
cardiac disease progression (6)
ECG abnormalities, diastolic dysfunction, MRI fibrosis, carrdiac cavity dilatation, systolic dysfunction, end stage heart failure
what happens at age 3-6 (3)
lordotic and waddling gait, Gower’s sign, muscle hypertrophy
which muscles become hypertrophied (5)
calf, glutes, vastus lateralis, deltoid, infraspinatus
what happens age 6-11
limb and torso muscle strength decreases
which muscles are spared
occulomotor
why are some muscles spared (3)
small fibre size, lower mechanical stress per unit surface membrane area, increased sarcolemmal expression of compensatory proteins
dystrophin gene mutation
Xp21
what does an Xp21 gene mutation lead to
dystrophin expression deficiency
