This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Integrated QBank, Subject name: Unknown
A 6-year-old boy presented with recurrent pyogenic abscess, runny nose, oral thrush & rash on perineal areas. Pus culture showed growth of Staphylococcus aureus. A test was performed whose finding is shown below. What is most common mode of inheritance of this disorder? 
Select and explain. 
A. Autosomal recessive, B. X linked recessive, C. Autosomal dominant, D. Mitochondrial inheritance
B: X linked recessive
Answer: B: X linked recessive 
Explanation: Image represents Nitroblue tetrazolium test which points to the diagnosis of CGD. Chronic granulomatous disease Immunodeficiency disorder Due to mutation in PHOX gene Also known as bridges good syndrome Has both autosomal recessive & X-linked recessive inheritance but X-linked recessive is most common. Characterised by recurrent infections by catalase positive organisms like s. Aureus, candida etc. The simplest and most rapid test for CGD is the NBT (Nitroblue tetrazolium) test. Neutrophils from a small sample of peripheral blood are activated to produce superoxide which is detected by the NBT, which is conveed from a yellow water-soluble compound to a dark-blue insoluble formazan that can be clearly detected microscopically.