The presence of an abnormal number of fragmented red blood cells (schistocytes) in the blood.

A form of hemolytic anemia that occurs in repeated episodes.

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)

Dysplasia in the erythroid lineage, which presents with a variety of morphological changes in the bone marrow, including nuclear budding or irregular nuclear contour in erythroblasts.

An excessive division of the lobes of the nucleus of a neutrophil.

The concentration of vitamin B12 in the blood circulation is below the lower limit of normal.

Increased concentration of ferritin in the blood circulation.

An increased amount of bilirubin in the blood.

An increased concentration of homocystine in the blood.

An elevated level of the enzyme lactate dehydrogenase in the blood circulation.

Hereditary folate malabsorption (HFM) is characterized by folate deficiency due to impaired intestinal folate absorption and impaired folate transport into the central nervous system. Findings include poor feeding, failure to thrive, and anemia. There can be leukopenia and thrombocytopenia, diarrhea and/or oral mucositis, hypoimmunoglobulinemia, and other immunologic dysfunction resulting in infections, most often Pneumocystis jirovecii pneumonia. Neurologic manifestations include developmental delays, cognitive and motor disorders, behavioral disorders, and seizures.

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)