| Image = | Caption = | DiseasesDB = | ICD10 = | ICD9 = | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshName = Juvenile+Primary+Lateral+Sclerosis | MeshNumber = | }}Juvenile primary lateral sclerosis (JPLS) ,also known as as primary lateral sclerois (PLSJ), is a rare genetic disorder, with a small number of reported cases, characterized by progressive weakness and stiffness of musc