PRKAR1A and Carney complex: As CNC is an autosomal dominant inherited syndrome and has high penetrance (almost 100%), first-degree relatives should begin screening (clinical, laboratory and imaging tests, if necessary) to investigate any abnormalities in the complex.4,7 Screening for PRKAR1A mutations in those affected and their families is not recommended at this stage, since such mutations are only present in a little more than 40% of the families with CNC.4,11