Which of the following anemias is characterized by an abnormality in the GPI anchor protein?

A Hereditary spherocytosis
B Paroxysmal nocturnal hemoglobinuria ✓
C Sickle cell anemia
D Thalassemia major

Explanation

Paroxysmal nocturnal hemoglobinuria is a rare form of anemia characterized by an acquired deficiency in the GPI anchor protein, which normally anchors proteins to the cell membrane.

Source

Wintrobe's Clinical Hematology
Hematology Hematology: Anemia Hematology: Anemia Hard MEDICAL Confidence: high