Question:easy
A boy presented with weakness in the lower limbs, calf hypertrophy, positive Gower's sign and an elevated CPK value of 10,000. The most likely diagnosis is:
A boy presented with weakness in the lower limbs, calf hypertrophy, positive Gower's sign and an elevated CPK value of 10,000. The most likely diagnosis is:
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Boy plus calf pseudohypertrophy plus Gower's sign plus very high CPK equals Duchenne.
Updated On: Jun 24, 2026
- Duchenne muscular dystrophy
- Spinal muscular atrophy
- Myotonia congenita
- Myotonic dystrophy
Show Solution
The Correct Option is A
Solution and Explanation
Treat each clue as a vote. A young boy is the first hint, because the leading dystrophy of childhood is X linked and therefore strikes males. Proximal lower limb weakness plus a positive Gower's manoeuvre, where the child walks his hands up his thighs to push himself upright, tells us the pelvic girdle is weak. Bulky calves that feel firm are pseudohypertrophy from fat and fibrous tissue replacing muscle. Finally a creatine kinase soaring to around $10000$ signals brisk muscle fibre breakdown.
Every one of those votes lands on Duchenne muscular dystrophy, a defect of the dystrophin gene that presents in early boyhood with exactly this constellation and with CPK in the thousands.
Now dismiss the contenders. Spinal muscular atrophy is an anterior horn cell disease with floppiness, fasciculations, and tongue twitching, but it spares the calves from pseudohypertrophy and keeps CPK near normal. Myotonia congenita is a chloride channel disorder producing stiffness and trouble letting go after a grip, sometimes with a muscular build, yet without the relentless proximal weakness or the sky high enzyme. Myotonic dystrophy leans on myotonia, distal rather than proximal weakness, facial wasting, cataracts, and frontal balding, with only modest CPK rise, none of which matches a small boy with hypertrophied calves and a CPK of $10000$.
\[\boxed{\text{Duchenne muscular dystrophy}}\]
Every one of those votes lands on Duchenne muscular dystrophy, a defect of the dystrophin gene that presents in early boyhood with exactly this constellation and with CPK in the thousands.
Now dismiss the contenders. Spinal muscular atrophy is an anterior horn cell disease with floppiness, fasciculations, and tongue twitching, but it spares the calves from pseudohypertrophy and keeps CPK near normal. Myotonia congenita is a chloride channel disorder producing stiffness and trouble letting go after a grip, sometimes with a muscular build, yet without the relentless proximal weakness or the sky high enzyme. Myotonic dystrophy leans on myotonia, distal rather than proximal weakness, facial wasting, cataracts, and frontal balding, with only modest CPK rise, none of which matches a small boy with hypertrophied calves and a CPK of $10000$.
\[\boxed{\text{Duchenne muscular dystrophy}}\]
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