chronic atrial and intestinal dysrhythmia

Chronic atrial and intestinal dysrhythmia is a multisystem condition that primarily affects the heart and the intestines, manifesting as a combination of atrial arrhythmias and intestinal pseudo-obstruction. It is caused by mutations in the SGO1 gene leading to a dysfunctional SGOL1 protein, which plays a crucial role in cellular processes. This condition typically presents in early life, with affected individuals experiencing significant challenges related to both cardiac rhythm and gastrointestinal motility. It is very rare, occurring in fewer than 1 in a million people.

The clinical presentation of chronic atrial and intestinal dysrhythmia is defined by a consistent pattern of features. Characteristic findings include chronic intestinal pseudo-obstruction, bradycardia, and sick sinus syndrome, along with failure to thrive and decreased body weight, all of which are reported in every affected individual. Some patients may also develop additional cardiac manifestations such as left atrial enlargement, bicuspid aortic valve, mitral regurgitation, pulmonic stenosis, ventricular escape rhythm, atrial fibrillation, or atrial flutter. Not all individuals experience every feature, and severity varies considerably.

Chronic atrial and intestinal dysrhythmia is caused by pathogenic variants in the SGO1 gene. The mutated SGOL1 protein resulting from these variants disrupts normal cellular functions, leading to the combined cardiac and gastrointestinal manifestations observed in this syndrome. This condition is inherited in an autosomal recessive pattern, meaning that an affected individual has received one mutated copy of the gene from each parent. It is more common when parents share a common ancestor, as the likelihood that both carry the same rare genetic variant increases, and each pregnancy has a 25% recurrence risk if both parents are carriers. Genetic counseling is highly recommended for families to understand these implications and to discuss family planning options. Associated genes include SGO1.