BACKGROUND AND OBJECTIVES: Kell antigens are encoded by the KEL gene on the long 
arm of chromosome 7. Kx antigen is encoded by the XK gene on the short arm of 
the X chromosome. Kell and Kx proteins in the red cell membrane are covalently 
linked by a disulphide bond. The McLeod phenotype is characterized by weakened 
expression of antigens in the Kell blood group system, absence of Km and Kx 
antigens, and acanthocytosis. It has an X-linked mode of inheritance with 
transmission through carrier females. Some males with the McLeod syndrome also 
have chronic granulomatous disease (CGD). It is generally believed that patients 
with non-CGD McLeod may develop anti-Km but not anti-Kx, but that those with CGD 
McLeod can develop both anti-Km and anti-Kx.
MATERIALS AND METHODS: We present serological data, DNA genotyping and gene 
sequencing, monocyte monolayer assay and neutrophil oxidative burst test from a 
patient with the McLeod phenotype without clinical evidence of CGD.
RESULTS: We report here the second example of a patient with non-CGD McLeod who 
developed anti-Kx in addition to anti-Km. Sequencing of our patient's XK gene 
confirmed the presence of a mutation resulting in a premature stop codon and 
lack of Kx protein in the red cell membrane, which is consistent with the 
diagnosis of McLeod syndrome. Neutrophil oxidative burst test was normal, 
indicating that our patient did not have CGD. The challenge of providing 10 
compatible blood units for multiple surgeries was met.
CONCLUSION: The second case of a rare entity, a patient with non-CGD McLeod who 
developed anti-Kx and anti-Km, was managed successfully with a combination of 
autologous donations and procurement of compatible units from national and 
international sources.