MYO5B and hyperinsulinemic hypoglycemia, familial, 4: The known causes of IC in the patients include biliary atresia (one case), defects in MYO5B (one case), and citrin deficiency (two cases), cytomegalovirus infection (two case), respiratory tract infection and urinary tract infection (six cases), while the etiology for the remaining 8 patients was unknown (Table 1).