Non-5q spinal muscular atrophies are different hereditary anterior horn cell diseases, clinical and genetically heterogeneous, not associated with a homozygous deletion of the motor neuron survival gene (SMN1) underlying the most known and classic form of spinal muscular atrophy. Identify these entities by their specific clinical features and be able to differentiate them from classical spinal muscular atrophy is an urgent need. Now more than ever, given the newly approved drug, to treat classic spinal muscular atrophy and the emerging knowledge that some non-classical forms also have a specific treatment. Such is the case for the deficiency of riboflavin transporters where timely diagnosis and treatment may allow saving the life of patients.