This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Leucocyte adhesion deficiency type 1 is seen in which of\nthe chromosome? \nSelect and explain. \nA. 1, B. 5, C. 21, D. X', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Key Concept: Patients with LAD1 have an inherited molecular defect that causes a deficiency of the β2\xa0integrin subunit, also called CD18, which is encoded by the ITGB2 gene found on chromosome 21.\xa0\nLAD/MPO\xa0\n\nLeukocyte Adhesion Deficiency (LAD) disorders -\xa0Autosomal recessive inheritance pattern\xa0\nLAD type 1 - deficiency of β2-integrin.\nLAD type 2 - deficiency of endothelial cell selectin that binds neutrophils.\nFirst manifestation in either type is delayed separation of the umbilical cord.\nSevere gingivitis, poor wound healing, and peripheral blood neutrophilic leukocytosis (loss of the marginating pool). NO PUS FORMATION .\nMyeloperoxidase (MPO) deficiency.\nDiffers from CGD in that both 02•-\xa0and H202 are produced (normal respiratory burst)\nAbsence of MPO prevents synthesis of HOCI.', 'role': 'assistant'}]