What are the symptoms? The main symptom is the person’s inability to breathe deeply enough, leading to a need for assisted ventilation, most commonly beginning shortly after birth. Affected individuals also do not feel breathlessness and so under-breathe during feeding, exercise or when concentrating. The condition ranges in severity with the worst affected under-breathing both during sleep and when awake. Those least affected may not present till older and may be mildly affected during sleep and with normal breathing when awake. Children with CCHS may have other problems related to the body’s automatic nervous system, including: Hirschsprung’s disease – a failure of the bowel to move normallyswallowing difficultiesheart rhythm disorders (see entry Heart Defects)increased risk of tumours of nerve tissue‘blue-breath holding’ episodes – stopping breathing and turning blue when cryingfainting episodesepileptic or absence seizures (see entry Epilepsy)learning difficulties (see entry Learning Disability)eye problems, such as squintsunusual responses to anaesthesticpoor temperature control. What are the causes? CCHS is caused by a mutation (a change) in the PHOX2B gene. This mutation affects the development of the foetus’ autonomic nervous system, which is responsible for involuntary processes such as breathing and heart rhythm. How is it diagnosed? The diagnosis of CCHS is confirmed by the genetic mutation, but there are some cases where this is negative and the diagnosis relies on recording under-breathing from sensors that measure levels of oxygen and carbon dioxide (the body’s waste gas). How is it treated? Treatment of CCHS involves providing assisted (mechanical) ventilation when the individual breathes inadequately on their own. No medication has been shown to sufficiently stimulate the breathing enough. The usual ventilator devices blow air into the lungs, through either a tracheostomy (a surgically created hole in the front of the neck), or a mask. In cases where ventilation is needed during both the day and night, this is given through the tracheostomy or, after infancy, by surgically implanted breathing pacemakers (small devices delivering an electrical stimulus) that stimulate the nerves to the diaphragm, the main muscle involved in breathing. Individuals with CCHS need regular monitoring of their oxygen levels with a sats monitor (pulse oximeter) and sometimes with a carbon dioxide monitor to identify inadequate ventilation. Giving additional oxygen alone would be inadequate treatment. Parents can be trained to look after a child’s ventilation at home. As children grow, their need for ventilation may change and so regular review is required. The condition is life-long, but most children do well, attend school and have a normal life while awake. Some children need bowel surgery or heart pacemakers for associated complications. Inheritance patterns and prenatal diagnosis Inheritance patternsThe mutation in the PHOX2B gene is passed to children in an autosomal dominant manner. Prenatal diagnosisThis is possible if a PHOX2B mutation has been found in one of the parents. Samples of cells from a foetus can be collected during the pregnancy and tested for the mutation in the PHOX2B gene. Is there support? CCHS Support Group Tel: 01423 421221Email: via website Website: cchssupport.co.uk The Group provides support for families affected by Congenital Central Hypoventilation Syndrome throughout the UK. It organises conferences for families to meet up and share experiences. These events are also an opportunity to invite CCHS physicians and researchers to share their insight on research and treatments. Group details last updated November 2019.