Folate-responsive megaloblastic anemia (MEGAF) is an autosomal recessive metabolic disorder characterized by megaloblastic anemia resulting from decreased folate transport into erythrocytes. Although serum levels of folate are normal, there is folate deficiency in tissues, including erythrocytes and possibly nerve cells. Serum homocysteine levels are increased and vitamin B12 levels may be decreased. Treatment with oral folate corrects the anemia and normalizes homocysteine (summary by Svaton et al., 2020)

Sitosterolemia is characterized by: Hypercholesterolemia (especially in children) which (1) shows an unexpected significant lowering of plasma cholesterol level in response to low-fat diet modification or to bile acid sequestrant therapy; or (2) does not respond to statin therapy; Tendon xanthomas or tuberous (i.e., planar) xanthomas that can occur in childhood and in unusual locations (heels, knees, elbows, and buttocks); Premature atherosclerosis, which can lead to angina, aortic valve involvement, myocardial infarction, and sudden death; Hemolytic anemia, abnormally shaped erythrocytes (stomatocytes), and large platelets (macrothrombocytopenia). On occasion, the abnormal hematologic findings may be the initial presentation or the only clinical feature of this disorder. Arthritis, arthralgias, and splenomegaly may sometimes be seen and one study has concluded that "idiopathic" liver disease could be undiagnosed sitosterolemia. The clinical spectrum of sitosterolemia is probably not fully appreciated due to underdiagnosis and the fact that the phenotype in infants is likely to be highly dependent on diet.