Worsening of the clinical-hematological picture in a patient with a rare PK-LR compound heterozygosis after mitral replacement.

We report a case of a patient affected by compound heterozygosis for two PK-LR gene mutations: p.R486W (c.1456C>T) and p.M403I (c.1209G>A). Our patient suffered from an initial moderate hemolytic anemia which subsequently evolved into a severe form after mitral prosthetic valve replacement for valve regurgitation. Thereafter, the clinical features evolved into a worsening of anemia, heart failure and pulmonary hypertension, in the absence of valve dysfunction. This clinical picture improved only after an intensive transfusion regimen. This case highlights aspects concerning the intricate balance between the risks and benefits of a mechanical prosthetic valve implant in PK-deficient patients.