D

Juvenile (aggressive) periodontitis is consistently linked to impaired neutrophil chemotaxis; studies show most affected patients have defective migration of neutrophils toward chemotactic stimuli, predisposing to rapid alveolar bone loss, while other neutrophil functions (lysis, phagocytosis) are not increased and cyclic neutropenia is a distinct entity [Clark 1977, PMID 591063; Van Dyke 1980, PMID 7358424].