A dad brought his 3 year-old male son for a quick evaluation of toothache. His son is complaining of rapidly worsening pain around his teeth and gums for the last 3 days. The boy’s past medical history is significant for recurrent bacterial infections, impaired physical and mental growth. In the physical examination, you noticed a child who looks small for his age with unusual facial features. Laboratory workup showed marked leukocytosis, defective expression of selectin ligands, a rare Bombay (hh) blood type at the ABO locus and the absence of sialyl Lewis X expression (CD15a). He responded well to antibiotics and oral fucose supplements. Which of the following is the most likely diagnosis in this patient?
