Pernicious anemia (also called Addison's anemia) is a type of red blood cell disorder caused by impaired vitamin B12 metabolism. Vitamin B12 is primarily absorbed by the small intestine, after being bound to intrinsic factor secreted by parietal cells of gastric mucosa. When this process is disrupted by conditions like atrophic gastritis, celiac disease, small bowel resection etc, B12 deficiency ensues.
Common risk factors in the development of<unk><unk>  leukemia include ionizing radiation, formaldehyde, benzene, older age and male gender.
Chronic myelogenous leukemia risk factors
Myelodysplastic syndrome risk factors
Acute lymphoblastic leukemia risk factors
Hairy cell leukemia risk factors
Myelofibrosis risk factors
Mast cell leukemia risk factors
B-cell prolymphocytic leukemia risk factors
Febrile neutropenia risk factors