False positives include other conditions with fatty infiltration of the ventricle, such as long-term excessive alcohol use and Duchenne or Becker muscular dystrophy. False negatives are common, however, because the disease progresses typically from the epicardium to the endocardium (with the biopsy sample coming from the endocardium), and the segmental nature of the disease. Also, due to the paper-thin right ventricular free wall that is common in this disease process, most biopsy samples are taken from the ventricular septum, which is commonly not involved in the disease process. A biopsy sample that is consistent with ACM would have > 3% fat, >40% fibrous tissue, and <45% myocytes. A post mortem histological demonstration of full thickness substitution of the RV myocardium by fatty or fibro-fatty tissue is consistent with ACM. Genetic testing
ACM is an autosomal dominant trait with reduced penetrance. Approximately 40–50% of ACM patients have a mutation identified in one of several genes encoding components of the desmosome, which can help confirm a diagnosis of ACM. Since ACM is an autosomal dominant trait, children of an ACM patient have a 50% chance of inheriting the disease-causing mutation. Whenever a mutation is identified by genetic testing, family-specific genetic testing can be used to differentiate between relatives who are at-risk for the disease and those who are not. ACM genetic testing is clinically available. Diagnostic criteria
There is no pathognomonic feature of ACM. The diagnosis of ACM is based on a combination of major and minor criteria.
Intussusception may refer to:

Intussusception (medical disorder)
Intussusception (blood vessel growth)
Rectal prolapse#Internal rectal intussusception