SNP Shot: Genomic Insights

Chronic atrial and intestinal dysrhythmia (CAID) is a condition that affects both the heart and the digestive tract. Individuals with CAID experience an irregular heartbeat due to sick sinus syndrome, a type of heart rhythm disturbance. Additionally, CAID disrupts the normal wave-like muscle movements (peristalsis) that move food through the intestines, leading to a digestive problem known as intestinal pseudo-obstruction. Both heart and digestive issues typically manifest by the time the individual reaches 20 years of age.

Sick sinus syndrome, also called sinus node dysfunction, occurs when the sinoatrial (SA) node malfunctions. The SA node, a group of specialized cells in the heart, acts as the body's natural pacemaker, initiating each heartbeat by generating electrical impulses. These impulses spread through the heart, triggering the heart muscle to contract and pump blood. In individuals with sick sinus syndrome, the SA node doesn't work properly, most commonly causing a slow heartbeat (bradycardia). However, sometimes it can cause a rapid heartbeat (tachycardia), or cycles of both fast and slow heartbeats (tachycardia-bradycardia syndrome). Symptoms related to these abnormal heart rhythms can include dizziness, lightheadedness, fainting (syncope), palpitations (a feeling of fluttering or pounding in the chest), and cognitive issues like confusion or memory loss. Many people with the condition may experience chest pain, shortness of breath, or extreme fatigue during physical activity.

Intestinal pseudo-obstruction results from impaired peristalsis, causing a buildup of partially digested food in the intestines. This leads to abdominal swelling (distention), abdominal pain, nausea, vomiting, and either constipation or diarrhea. Those affected often experience a decreased appetite and difficulty absorbing nutrients, which can lead to malnutrition. The symptoms are similar to those caused by a physical blockage (obstruction) in the intestine, such as a tumor, but in intestinal pseudo-obstruction, no such blockage exists.

Inheritance:

CAID is inherited in an autosomal recessive manner. This means that an individual must inherit two copies of the mutated gene, one from each parent, to develop the condition. The parents, who each carry only one copy of the mutated gene, are typically asymptomatic carriers.