Spinal Muscular atrophy diagnosis

In order to be diagnosed with Spinal muscular atrophy, symptoms need to be present. In most cases a diagnosis can be made by the SMN gene test, which determines whether there is at least one copy of the SMN1 gene by looking for its unique sequences (that distinguish it from the almost identical SMN2) in exons 7 and 8. In some cases, when the SMN gene test is not possible or does not show any abnormality, other tests such as an EMG electromyography (EMG) or muscle biopsy may be indicated.