Chronic atrial and intestinal dysrhythmia
What is chronic atrial and intestinal dysrhythmia?
Chronic atrial and intestinal dysrhythmia (CAID) is a disorder affecting the heart and the digestive system. CAID disrupts the normal rhythm of the heartbeat; affected individuals have a heart rhythm abnormality called sick sinus syndrome. The disorder also impairs the rhythmic muscle contractions that propel food through the intestines (peristalsis), causing a digestive condition called intestinal pseudo-obstruction. The heart and digestive issues develop at the same time, usually by age 20.
Sick sinus syndrome (also known as sinus node dysfunction) is an abnormality of the sinoatrial (SA) node, which is an area of specialized cells in the heart that functions as a natural pacemaker. The SA node generates electrical impulses that start each heartbeat. These signals travel from the SA node to the rest of the heart, signaling the heart (cardiac) muscle to contract and pump blood. In people with sick sinus syndrome, the SA node does not function normally, which usually causes the heartbeat to be too slow (bradycardia), although occasionally the heartbeat is too fast (tachycardia) or rapidly switches from being too fast to being too slow (tachycardia-bradycardia syndrome). Symptoms related to abnormal heartbeats can include dizziness, light-headedness, fainting (syncope), a sensation of fluttering or pounding in the chest (palpitations), and confusion or memory problems. During exercise, many affected individuals experience chest pain, difficulty breathing, or excessive tiredness (fatigue).
In intestinal pseudo-obstruction, impairment of peristalsis leads to a buildup of partially digested food in the intestines, abdominal swelling (distention) and pain, nausea, vomiting, and constipation or diarrhea. Affected individuals experience loss of appetite and impaired ability to absorb nutrients, which may lead to malnutrition. These symptoms resemble those caused by an intestinal blockage (obstruction) such as a tumor, but in intestinal pseudo-obstruction no such blockage is found.
Read more about intestinal pseudo-obstruction and sick sinus syndrome.
How common is chronic atrial and intestinal dysrhythmia?
The prevalence of CAID is unknown. At least 17 affected individuals have been described in the medical literature.
What genes are related to chronic atrial and intestinal dysrhythmia?
CAID is caused by mutations in the SGOL1 gene. This gene provides instructions for making part of a protein complex called cohesin. This protein complex helps control the placement of chromosomes during cell division. Before cells divide, they must copy all of their chromosomes. The copied DNA from each chromosome is arranged into two identical structures, called sister chromatids, which are attached to one another during the early stages of cell division. Cohesin holds the sister chromatids together, and in doing so helps maintain the stability of chromosomal structure during cell division.
Researchers suggest that SGOL1 gene mutations may result in a cohesin complex that is less able to hold sister chromatids together, resulting in decreased chromosomal stability during cell division. This instability is thought to cause early aging (senescence) of cells in the intestinal muscle and in the SA node, resulting in problems maintaining proper rhythmic movements of the heart and intestines and leading to the signs and symptoms of CAID.
It is unclear why SGOL1 gene mutations specifically affect the heart and intestines in CAID. Researchers suggest that the activity (expression) of the SGOL1 gene in certain embryonic tissues or a particular function of the SGOL1 protein in the SA node and in cells that help control peristalsis may account for the features of the disorder.
Read more about the SGOL1 gene.
How do people inherit chronic atrial and intestinal dysrhythmia?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of chronic atrial and intestinal dysrhythmia?
These resources address the diagnosis or management of chronic atrial and intestinal dysrhythmia and may include treatment providers.
- Children's Hospital of Pittsburgh: Chronic Intestinal
Pseudo-obstruction - Genetic Testing Registry: Chronic atrial and intestinal
dysrhythmia - Health Topic: Nutritional
Support - Health Topic: Pacemakers and Implantable
Defibrillators - MedlinePlus Encyclopedia: Heart
Pacemakers - National Heart, Lung, and Blood Institute: What is a
Pacemaker?
You might also find information on the diagnosis or management of chronic atrial and intestinal dysrhythmia in Educational 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 chronic atrial and intestinal dysrhythmia?
You may find the following resources about chronic atrial and intestinal dysrhythmia helpful. These materials are written for the general public.
- MedlinePlus - Health information (7 links)
- Additional NIH Resources - National Institutes of Health
- Educational resources - Information pages (2 links)
- Patient support - For patients and families (5 links)
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
- Genetic Testing Registry - Repository of genetic test information (1 link)
PubMed - Recent literatureOMIM - Genetic disorder catalog
What other names do people use for chronic atrial and intestinal dysrhythmia?
- CAID
- cohesinopathy affecting heart and gut rhythm
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 chronic atrial and intestinal dysrhythmia?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
- What does it mean if a disorder seems to run in my family?
- What are the different ways in which a genetic condition can be inherited?
- If a genetic disorder runs in my family, what are the chances that my children will have the condition?
- Why are some genetic conditions more common in particular ethnic groups?
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding chronic atrial and intestinal dysrhythmia?
atrial ; autosomal ; autosomal recessive ; bradycardia ; cardiac ; cell ; cell division ; chromosome ;chronic ; constipation ; digestive ; digestive system ; distention ; DNA ; embryonic ; fainting ; gene ;inherited ; obstruction ; pacemaker ; palpitations ; prevalence ; protein ; recessive ; SA node ; sinus ;sinus node ; syncope ; syndrome ; tachycardia ; tumor
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (3 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
No hay comentarios:
Publicar un comentario