SMNDC1 is a vital splicing factor obligatory for spliceosome assembly which is a part of the SMN family. SMNDC1 has one Tudor domain with significant similarity to Survival Motor Neuron (SMN) and is expressed in heart, pancreas and skeletal muscle, localizing to Cajal bodies and nuclear speckles. Mutations in SMNDC1 are cause of autosomal recessive proximal spinal muscular atrophy.