A 3 year old child was having difficulty walking.He had not met his developmental milestones.His legs actually looked quite strong,with apparently muscular calves.However,the paediatric neurologist ordered a muscle biopsy,which is shown in the accompanying photomicrograph.On the right is an immunohistochemical stain for dystrophin protein.
A)Becker muscular dystrophy
B)Duchenne muscular dystrophy
C)Mitochondrial myopathy
D)Neurogenic muscular atrophy
E)Polymyositis

Question

A 3 year old child was having difficulty walking.He had not met his developmental milestones.His legs actually looked quite strong,with apparently muscular calves.However,the paediatric neurologist ordered a muscle biopsy,which is shown in the accompanying photomicrograph.On the right is an immunohistochemical stain for dystrophin protein. 
A)Becker muscular dystrophy 
B)Duchenne muscular dystrophy 
C)Mitochondrial myopathy 
D)Neurogenic muscular atrophy 
E)Polymyositis

Quizplus · Accepted Answer

This is a case of Duchenne muscular dystrophy,often characterised by the pseudohypertrophy of the calf muscles.Histologically,there is destruction of muscle fibres with replacement of muscle by fibrous tissue (F).Residual fibres exhibit a markedly abnormal variation in fibre size,with atrophy of some fibres and hypertrophy of others.Immunocytochemistry can be used to reveal the pattern of staining with antibodies to dystrophin,which is normally ubiquitous on muscle fibres.As shown in micrograph,in this case there is abnormal patchy and pale staining of many fibres (P).

A 3 Year Old Child Was Having Difficulty Walking