has material basis in germline mutation in SELENON rigid spine muscular dystrophy 1 https://github.com/monarch-initiative/mondo/issues/4521 https://github.com/monarch-initiative/mondo/issues/9976 https://www.malacards.org/card/congenital_myopathy_3_with_rigid_spine SCTID:240063002 RSS minicore myopathy, severe classic form This term is scheduled to be merged with MONDO:0100100 SELENON-related myopathy, based on the fact that the concept of these 2 terms are the same. This ID will therefore be obsoleted and replaced with MONDO:0100100 RSMD1 NCIT:C126691 rigid spine muscular dystrophy 1 muscular dystrophy, congenital, Eichsfeld type classic multiminicore myopathy OMIM:602771 DOID:0110633 muscular dystrophy, rigid spine, 1 classic MmD multiminicore disease, severe classic form MEDGEN:98047 SELENON rigid spine syndrome MDRS1 MONDO:0011271 myopathy, SEPN1-related 2026-08-01 GARD:0024786 multicore myopathy, severe classic form rigid spine muscular dystrophy type 1 classic multiminicore disease UMLS:C0410180 rigid spine syndrome muscular dystrophy, congenital, merosin-positive, with early spine rigidity An inherited muscular dystrophy caused by mutations in the SEPN1 gene. It is characterized by severe limitation in flexion of the dorsolumbar and cervical spine, due to contracture of the spinal extensors. It leads to loss of movement of the spine and the thoracic cage. rigid spine syndrome caused by mutation in SELENON multiminicore myopathy rigid spine syndrome SELENON-related myopathy