Cyclic vomiting syndrome is a disorder that causes recurrent episodes of nausea, vomiting, and tiredness (lethargy). This condition is diagnosed most often in young children, but it can affect people of any age.

Although the causes of cyclic vomiting syndrome have yet to be determined, researchers have proposed several factors that may contribute to the disorder. These factors include changes in brain function, hormonal abnormalities, and gastrointestinal problems. Many researchers believe that cyclic vomiting syndrome is a migraine-like condition, which suggests that it is related to changes in signaling between nerve cells (neurons) in certain areas of the brain. Many affected individuals have abnormalities of the autonomic nervous system, which controls involuntary body functions such as heart rate, blood pressure, and digestion. Based on these abnormalities, cyclic vomiting syndrome is often classified as a type of dysautonomia.

The exact prevalence of cyclic vomiting syndrome is unknown; estimates range from 4 to 2,000 per 100,000 children. The condition is diagnosed less frequently in adults, although recent studies suggest that the condition may begin in adulthood as commonly as it begins in childhood.

In most cases of cyclic vomiting syndrome, affected people have no known history of the disorder in their family. However, many affected individuals have a family history of related conditions, such as migraines, irritable bowel syndrome, or depression, in their mothers and other maternal relatives. This family history suggests an inheritance pattern known as maternal inheritance or mitochondrial inheritance, which applies to genes contained in mtDNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, children can only inherit disorders resulting from mtDNA mutations from their mother. These disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass traits associated with changes in mtDNA to their children.

Published Date: March 01, 2014
Published By: National Institutes of Health