Type your tag names separated by a space and hit enter


MATURATION DISORDERS is a topic covered in the Harrison's Manual of Medicine.

To view the entire topic, please or purchase a subscription.

Harrison’s Manual of Medicine 19th edition provides 600+ internal medicine topics in a rapid-access format. Download Harrison’s App to iPhone, iPad, and Android smartphone and tablet. Explore these free sample topics:

Harrison’s Manual of Medicine - App + Web

-- The first section of this topic is shown below --

These result from either defective hemoglobin synthesis, leading to cytoplasmic maturation defects and small relatively empty red cells, or abnormally slow DNA replication, leading to nuclear maturation defects and large full red cells. Defects in hemoglobin synthesis usually result from insufficient iron supply (iron deficiency) or decreased globin production (thalassemia) or are idiopathic (sideroblastic anemia). Defects in DNA synthesis are usually due to nutritional problems (vitamin B12 and folate deficiency), toxic (methotrexate or other cancer chemotherapeutic agent) exposure, or intrinsic marrow maturation defects (refractory anemia, myelodysplasia).

Laboratory tests useful in the differential diagnosis of the microcytic anemias are shown in Table 62-2. Mean corpuscular volume (MCV) is generally 60–80 fL. Increased lactate dehydrogenase (LDH) and indirect bilirubin levels suggest an increase in RBC destruction and favor a cause other than iron deficiency. Iron status is best assessed by measuring SI, TIBC, and ferritin levels. Macrocytic MCVs are >94 fL. Folate status is best assessed by measuring red blood cell folate levels. Vitamin B12 status is best assessed by measuring serum B12, homocysteine, and methylmalonic acid levels. Homocysteine and methylmalonic acid levels are elevated in the setting of B12 deficiency.

TestsIron DeficiencyInflammationThalassemiaSideroblastic Anemia
SmearMicro/hypoNormal micro/hypoMicro/hypo with targetingVariable
SI<30<50Normal to highNormal to high
Percent saturation<1010–2030–8030–80
Ferritin (μg/L)<1530–20050–30050–300
Hemoglobin pattern on electrophoresisNormalNormalAbnormal with β thalassemia; can be normal with α thalassemiaNormal
Abbreviations: SI, serum iron; TIBC, total iron-binding capacity.

-- To view the remaining sections of this topic, please or purchase a subscription --


* When formatting your citation, note that all book, journal, and database titles should be italicized* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - MATURATION DISORDERS ID - 623586 ED - Fauci,Anthony S, ED - Hauser,Stephen L, ED - Jameson,J Larry, ED - Kasper,Dennis L, ED - Longo,Dan L, ED - Loscalzo,Joseph, BT - Harrison's Manual of Medicine UR - https://harrisons.unboundmedicine.com/harrisons/view/Harrisons-Manual-of-Medicine/623586/all/MATURATION_DISORDERS PB - McGraw Hill Inc. ET - 19 DB - Harrison's Manual of Medicine DP - Unbound Medicine ER -