By definition, extrinsic causes of hemolysis are abnormalities in the environment in which the red blood cells (RBCs), usually normal themselves, circulate. These abnormalities can be acute or chronic in nature. They can arise from congenital lesions but usually result…
Autoimmune hemolytic anemia (AIHA) is a rare autoimmune disease caused by autoimmune-mediated destruction of red blood cells (RBCs) by autoantibodies with various properties and target specificities. Exact laboratory diagnosis may sometimes be difficult; therefore, experienced diagnostic reference centers play an…
Characterization of the structure and function of red blood cell (RBC) membrane proteins and their genes ( Fig. 46.1 ) has led to considerable advances in our understanding of the molecular pathology of membrane-associated disorders, including the definition and characterization…
Red blood cells (RBCs) are highly specialized cells with the sole function of delivering oxygen to the tissues. During oxygen delivery, a highly destructive reactive oxygen species (ROS)—such as superoxide—is generated from a small fraction of the oxygen released from…
Hemoglobinopathies are inherited diseases caused primarily by mutations affecting the globin genes. Nearly 1000 mutations are known to alter the structure, expression, or developmental regulation of individual globin genes and the hemoglobins that they encode. Of these, only a few…
Hemoglobinopathies are the most common genetic diseases in humans. In sickle cell disease (SCD), a single nucleotide substitution (GTG for GAG, rs334 ) in the sixth codon of the β-globin gene produces an abnormal sickle hemoglobin (HbS). Due to a…
Since it was recognized as the “first molecular disease,” sickle cell anemia (HbSS) caused by homozygosity for the mutant sickle beta-globin gene has provided the classic paradigm for single-gene disorders. Predominant clinical features include hemolytic anemia, episodic painful vasoocclusive events,…
The thalassemia syndromes are a heterogeneous group of inherited anemias which result from defects in the synthesis of one or more of the globin chain subunits of the hemoglobin (Hb) tetramer. The basic defect, decreased or absent production of a…
The term megaloblastic anemia is used to describe a group of disorders characterized by a distinct morphologic pattern in hematopoietic cells. A common feature is a defect in deoxyribonucleic acid (DNA) synthesis, with lesser alterations in ribonucleic acid (RNA) and…
The porphyrias and the sideroblastic anemias are metabolic disorders that involve defects in heme biosynthesis. Most forms of porphyria are inherited in a Mendelian autosomal dominant pattern, but some types are recessive, and others are acquired through exposure to porphyrinogenic…