A 34 year old male experiences shortness of breath with minimal exertion. Physical examination reveals elevated jugular venous pressure markedly worse with inspiration, a regular rhythm with an S4 heart sound and 2+ lower extremity pitting edema. Laboratory studies are normal. Cardiac biopsy revealed apple green birefringence with congo red staining. Genetic testing reveals a mutation in the transthyretin gene. Which of the following is the correct diagnosis?
A. Restrictive cardiomyopathy
B. Dilated cardiomyopathy
C. Constrictive pericarditis
D. Hypertrophic obstructive cardiomyopathy
E. Chagas cardiomyopathy