spinal muscular atrophy screening
Also written as: SMA — Spinal Muscular Atrophy
Molecular genetic testing in newborns to detect deletions in the SMN1 gene causing progressive muscle weakness.
Full Definition
Spinal muscular atrophy (SMA) screening represents one of the newest additions to newborn screening panels, using molecular genetic techniques to detect deletions in the survival motor neuron 1 (SMN1) gene. SMA is a progressive neuromuscular disorder characterized by degeneration of motor neurons in the spinal cord, leading to muscle weakness and atrophy. The screening test typically uses real-time PCR to detect homozygous deletions of SMN1 exon 7, which account for approximately 95% of SMA cases. Early identification is crucial because new treatments like nusinersen and gene therapy are most effective when initiated before symptom onset, potentially preventing irreversible motor neuron loss.
Usage
Usage note: Capitalize when referring to the specific disorder; lowercase in general discussions of muscle conditions.
In Context
- "Spinal muscular atrophy screening uses PCR amplification to detect SMN1 gene deletions." — Laboratory protocol
- "The addition of spinal muscular atrophy screening to the panel required significant laboratory infrastructure investment." — Program evaluation report