The diagnosis of spinal muscular atrophy is made after the sudden or gradual onset of specific symptoms and after diagnostic testing. During the physical examination, the physician will obtain a complete medical history of patients, and he/she may also ask if there is a family history of any medical problems. Diagnostic tests that may be performed to confirm the diagnosis of spinal muscular atrophy include the following:
1. Blood tests2. Muscle biopsy - a small sample of the muscle is removed and examined to determine and confirm a diagnosis.3. Genetic tests - diagnostic tests that evaluate for conditions that have a tendency to run in families.4. Electromyogram (EMG) - a test that measures the electrical activity of a muscle or a group of muscles. An EMG can detect abnormal electrical muscle activity due to diseases and neuromuscular conditions.