Spinal muscular atrophy
All types of SMA are diagnosed through a blood test (genetic testing) to determine whether both copies of the SMN1 gene have a fault (deletion) responsible for SMA. A positive test will result in a diagnosis of 5q SMA.
Counting the number of SMN2 genes can be a helpful indicator for the prognosis of the condition (how it will develop). It can, therefore, guide the best care and management. The number of SMN2 copies can also be a factor in entry criteria for clinical trials.