In previousstudies, CP had lower BNP levels as compared to those of other restrictivesyndromes, such as restrictive cardiomyopathy, and that measurement could be usefulfor the differential diagnosis with other restrictive syndromes.17-19 Thus, in patients with predominantly right HF and normal ormildly elevated BNP levels, CP should be considered in the differentialdiagnosis. The gene discussed is NPPB; the disease is hydrops fetalis.