viernes, 28 de marzo de 2014

Cyclic vomiting syndrome - Genetics Home Reference

Cyclic vomiting syndrome - Genetics Home Reference

Genetics Home Reference: your guide to understanding genetic conditions



Cyclic vomiting syndrome

What is cyclic vomiting syndrome?

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.
The episodes of nausea, vomiting, and lethargy last anywhere from an hour to 10 days. An affected person may vomit several times per hour, potentially leading to a dangerous loss of fluids (dehydration). Additional symptoms can include unusually pale skin (pallor), abdominal pain, diarrhea, headache, and an increased sensitivity to light (photophobia) or to sound (phonophobia). In most affected people, the signs and symptoms of each attack are quite similar. These attacks can be debilitating, making it difficult for an affected person to go to work or school.
Episodes of nausea and vomiting can be triggered by a variety of factors. The most common triggers are emotional excitement and infections. Other triggers can include periods without eating (fasting), temperature extremes, lack of sleep, overexertion, allergies, ingesting certain foods or alcohol, and menstruation.
If the condition is not treated, attacks typically occur four to 12 times per year. Between episodes, vomiting is absent, and nausea is either absent or much reduced. However, many affected people experience other symptoms during and between episodes, including pain, digestive disorders such as gastroesophageal reflux and irritable bowel syndrome, and fainting spells (syncope). People with cyclic vomiting syndrome are also more likely than people without the disorder to experience depression, anxiety, and panic disorder. It is unclear whether all of these other health conditions are directly related to nausea and vomiting.
Cyclic vomiting syndrome is generally considered to be a variant of migraines, which are severe headaches often associated with pain, nausea, vomiting, and extreme sensitivity to light and sound. Many people with cyclic vomiting syndrome have a family history of migraines. Attacks of nausea and vomiting in childhood may be replaced by migraine headaches as an affected person gets older.
Most people with cyclic vomiting syndrome have normal intelligence, although some affected people have experienced developmental delay or intellectual disability. Affected individuals with muscle weakness (myopathy) and seizures have also been reported. People with these additional features are said to have cyclic vomiting syndrome plus.

How common is cyclic vomiting syndrome?

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.

What are the genetic changes related to cyclic vomiting syndrome?

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.
Some cases of cyclic vomiting syndrome, particularly those that begin in childhood, may be related to genetic changes in mitochondrial DNA. Mitochondria are structures within cells that convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA (known as mitochondrial DNA or mtDNA).
Several changes in mitochondrial DNA have been associated with cyclic vomiting syndrome. Some of these changes alter single DNA building blocks (nucleotides), whereas others rearrange larger segments of mitochondrial DNA. These changes likely impair the ability of mitochondria to produce energy. Defects in energy production may lead to symptoms during periods when the body requires more energy, such as when the immune system is fighting an infection. However, it remains unclear how changes in mitochondrial function are related to episodes of nausea, vomiting, and lethargy, or to migraines, in people with this condition.
Read more about mitochondrial DNA.

How do people inherit cyclic vomiting syndrome?

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, 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 mitochondrial DNA. Disorders with mitochondrial inheritance can appear in every generation of a family and can affect both males and females. However, because mitochondria can be passed from one generation to the next only through egg cells (not through sperm cells), only females pass mitochondrial conditions to their children.

Where can I find information about diagnosis or management of cyclic vomiting syndrome?

These resources address the diagnosis or management of cyclic vomiting syndrome and may include treatment providers.
You might also find information on the diagnosis or management of cyclic vomiting syndrome inEducational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

Where can I find additional information about cyclic vomiting syndrome?

You may find the following resources about cyclic vomiting syndrome helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for cyclic vomiting syndrome?

  • abdominal migraine
  • CVS
  • cyclical vomiting
  • cyclical vomiting syndrome
  • periodic vomiting
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about cyclic vomiting syndrome?

Where can I find general information about genetic conditions?

What glossary definitions help with understanding cyclic vomiting syndrome?

References (10 links)



The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.

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