McLeod syndrome

The McLeod phenotype (weak Kell antigens and no K_x antigen) is associated with acanthocytosis (a condition in which red cells have thorny projections) and a compensated hemolytic anemia. There is evidence that Duffy-negative human red cells are resistant to infection by Plasmodium knowlesi, a simian malaria…

…protein is absent, resulting in McLeod syndrome. Characteristics of this syndrome include acanthocytosis (thorny projections on red blood cells) and reduced Kell antigen expression. These abnormalities often lead to defects in muscle and nerve function that manifest as disordered movement, psychological disturbance, and loss of reflexes.