​What is Pathology - What are the most common congenital leukocyte function defects?

​What is Pathology - What are the most common congenital leukocyte function defects? 
Leukocyte function abnormalities are uncommon, occurring in less than 1 in 10,000 babies. These "natural experiments" are significant, however, because they shed light on the pathophysiology of leukocyte functions and how these cells fight infections. The following are some of the most common examples of aberrant leukocyte function: a)Leukocyte adhesion defects: Deficiencies of numerous leukocyte adhesion molecules, integrins, and enzymes that generate the carbohydrate ligands for the selectins fall into this category. 
b) Phagocytosis Defects: Opsonization is hampered by a lack of C3 complement. Chediak–Higashi syndrome is characterised by abnormal leukocyte migration and phagocytosis due to a deficiency in microtubule polymerization. Neutrophils are characterised by large granules that do not degranulate when stimulated. 
c) Defective bactericidal activity: NADPH oxidase deficiency is the most common impairment in children with chronic granulomatous illness. The leukocytes with this condition are unable to produce superoxide, impairing the oxygen-dependent killing of germs. These children are particularly vulnerable to infections caused by catalase-positive bacteria like Staphylococcus aureus. Streptococci that lack catalase are less harmful. These bacteria produce peroxide, which the leukocytes employ to produce hypochloric acid and kill pathogens. The inability of leukocytes to create H2O2 and hypochloric acid is characterised by myeloperoxidase deficiency. Children that are infected are more susceptible to fungal infections.