BackgroundChiari II malformation occurs in one of 1000 live births and causes posterior fossa malformation. In Chiari II malformation, a lumbosacral meningomyelocele is nearly always present. Achondroplasia is the most common cause of dwarfism, occurring in one of 26,000 live births. Both Chiari II malformation and achondroplasia can cause compression at the craniocervical junction and consecutive hydrocephalus.Case presentationThe case of a three-year-old male with Chiari II malformation, lumbosacral meningomyelocele, and achondroplasia is presented. To the authors' knowledge, this is the second such case that has been reported so far. A surgical therapy of a lumbosacral meningomyelocele and an implantation of a ventriculoperitoneal shunt was performed in the first month after birth. At the age of two years, occipitoatlantoaxial stenosis required spinal decompression and laminectomy. The child presented in the outpatient department with life-threatening respiratory dysregulation, comprising prolonged expiratory apnoea with cyanosis (PEAC), acquired central hypoventilation syndrome, central sleep apnoea and obstructive sleep apnoea. He also presented with delayed language development, paraplegia, a neurogenic bladder, and dwarfism. The patient received non-invasive ventilation and had an individually adapted set of assistive and therapeutic devices. Cough insufficiency necessitated the adaption of mechanical insufflation-exsufflation. Speech and language therapy, physiotherapy, and occupational therapy were performed regularly. The patient started attending kindergarten just before his fourth birthday. At his one year follow-up, the patient's language capacities substantially improved and PEAC was not reported anymore.ConclusionWhen osseous, cerebral, and spinal disease are accompanied by life-threatening respiratory impairment, the following factors can reduce the impact of disability and can foster participation: treatment by an interdisciplinary team, the availability of assistive and rehabilitative technologies, living in a barrier-free home, a developmentally appropriate environment, and the continuous presence of trained caregivers.