Genetic testing for spinal muscular atrophy is relevant in several distinct clinical situations:

*Diagnostic testing in a symptomatic infant or child: Any infant or child presenting with hypotonia, delayed motor milestones, or unexplained proximal muscle weakness should be evaluated for SMN1 gene deletion or mutation, since spinal muscular atrophy is one of the more common genetic causes of infantile hypotonia and a timely diagnosis directly affects treatment decisions.
*Carrier screening in couples planning a pregnancy or in early pregnancy: Since spinal muscular atrophy is autosomal recessive and carriers are asymptomatic, carrier screening can identify couples where both partners carry an altered SMN1 gene copy, allowing informed reproductive decision-making before or during pregnancy.
*Family history of spinal muscular atrophy: Relatives of an affected individual, particularly siblings of an affected child and individuals planning a family where a relative has been diagnosed, benefit from carrier testing to understand their own reproductive risk.
*Newborn screening programs: In regions where spinal muscular atrophy has been added to newborn screening panels, testing at birth allows identification before symptoms appear, which is particularly valuable given that early treatment initiation, before substantial motor neuron loss, is associated with better functional outcomes. Newborn screening for spinal muscular atrophy is expanding but not yet universal across India, so awareness among clinicians remains important for infants who may not have access to it.
*Prenatal diagnosis: For couples already known to be carriers, prenatal testing can determine whether a pregnancy is affected, allowing families to plan and prepare, including early referral to specialist care if the fetus is found to be affected.

Genetic counseling is recommended alongside testing in each of these situations, so that individuals and families understand the implications of results, including residual risk, the meaning of SMN2 copy number when relevant, and the reproductive and clinical options available to them. Due to high carrier frequency of spinal muscular atrophy, carrier screening for spinal muscular atrophy is offered via deletion/duplication analysis as a primary screening for a couple seeking preconceptional counseling.