The pathogenesis was osteopsathyrosis and viral encephalitis in 1 case; neurofibromatosis type‐1 (NF‐1), Chiari malformation, and transverse myelitis in two cases each; spinal muscular atrophy (SMA) in three cases, iatrogenic kyphosis in three cases; cerebral palsy in four cases; degenerative scoliosis (DS) in eight cases and poliomyelitis in 13 cases. The gene discussed is NF1; the disease is viral encephalitis.