Spinal Muscular Atrophy: SMN1 Genotyping

Diagnostic Use

Spinal muscular atrophy (SMA) is characterised by degeneration of lower motor neurons in the spinal cord, causing progressive paralysis of the limbs and trunk, followed by muscle atrophy. SMA is one of the most frequent autosomal recessive diseases, with a carrier frequency of 1 in 50 and is the most common genetic cause of childhood mortality. The phenotype is extremely variable, and patients are classified as SMA type I-III based on age at onset and clinical course. Over 95% of SMA patients display mutations in the survival motor neuron 1 (SMN1) gene on chromosome 5q13, and greater than 96% of these are homozygous for the deletion of exons 7 and 8 of this gene. Genetic analysis for this deletion provides an efficient diagnosis for this disorder.


Genetics - Molecular Pathology

Delphic Registration Code


Constituent Tests


SMA gene deletion
SMN1 Deletion Analysis
Spinal Muscular Atrophy Genetic Deletion

Turnaround Time

4 weeks

Test Code