<prompt> A child present with recurrent episodes of sinopulmonary infection by bacteria with polysaccharide rich capsule. Deficiency of which of the following immunoglobulin subclasses should be specifically investigated?IgAIgG1IgG2IgA IgG2  <response>: Ans. is d i.e., IgAIgG2Ref: Jawetz, 27the, p. 149 IgG2 immunodeficiency is the most common subclass disorder associated with recurrent infections by polysaccharide encapsulated bacteria. Such infections are more frequent in patients with associated IgA deficiency. 