RBCs are microcytic, hypochromic. No significant anemia. Hemoglobin shows a decrease in Hb A 2 . Caused by decreased synthesis of beta chains. Symptoms of anemia, splenomegaly, icterus.
Cells are microcytic.
Examination of peripheral smear shows target cells, cigar-shaped cells, and basophilic stippling. Genetic counseling is necessary. Both genes for beta-chain synthesis defective or missing. Manifestations begin at approximately 4 to 6 months of life. There is pronounced wasting, jaundice, slow growth and development, and delayed onset of secondary sex features.