Prenatal diagnosis of spinal muscular atrophy: clinical experience and molecular genetics of SMN gene analysis in 36 cases

Introduction: prenatal diagnosis in families at risk for spinal muscular atrophy (SMA) mainly of type 1 is often applied due to the high incidence, most severe and newborn outcome of the disease.

Case: we present our clinical experience for 36 families with history of having at least one child with homozygous deletions of the SMN1 gene between. Seventeen families requested for prenatal prediction and of these cases, 8 fetuses were diagnosed to be at risk of developing the disease and the parents decided to terminate the pregnancy. Nine fetuses were detected with no homozygous deletion of the SMN1 and reached to full term delivery. Follow-up of live born children and abortion products never led to false or negative result.

Conclusion: therefore, application of SMN1 deletion detection by simple PCR assay in families with homozygous deletion of the SMN1 gene could be suggested for prenatal prediction in such families.