This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: New Born Infants, Subject name: Pediatrics
Lack of leucocyte adhesion molecules (LAM) is associated with: 
Select and explain. 
A. Delayed fall of umbilical cord, B. Normal chemotaxis, C. Complement opsonization, D. Neutropenia
A: Delayed fall of umbilical cord
Answer: A: Delayed fall of umbilical cord 
Explanation: a. Delayed fall of umbilical cord(Ref: Nelson's 20/e p 1027, Ghai 8/e p 187)Leukocyte adhesion deficiency (LAD)Salient featuresLAD type 1LAD type 2InheritanceAutosomal recessiveAutosomal recessiveBasic defectDefect in CD 18 moleculeQ required for biosynthesis of B2 chain shared by LFA-1 & Mac-1 integrinsAbsence of Sialyl-Lewis X, the fucose-containing ligand for P & E-selection, due to defect in fucosyl-transferase responsible for binding fucose moieties to protein backbonesClinical featuresRecurrent bacterial infections, delayed separation of umbilical cord stumpQRecurrent bacterial infections, Bombay blood groupQ and mental retardation