Any prenatal-onset spinal muscular atrophy with congenital bone fractures in which the cause of the disease is a mutation in the ASCC1 gene. The disease is MONDO_0014807 (spinal muscular atrophy with congenital bone fractures 2). Also known as: ASCC1 prenatal-onset spinal muscular atrophy with congenital bone fractures, SMABF2, prenatal-onset spinal muscular atrophy with congenital bone fractures caused by mutation in ASCC1, spinal muscular atrophy with congenital bone fractures type 2.