Hemoglobin constant spring defined by specific oligonucleotide hybridization and hemoglobin D Punjab ( beta super(121) arrow right super(Gln)) in a Batak Indonesian family

A Batak Indonesian from North Sumatra with hemoglobin (Hb) D Punjab ( alpha sub(2) beta sub(2) super(121) arrow right super(Gln)) and hemoglobin Constant Spring (Hb CoSp) is described. The 24-year-old man did not have clinical symptoms, and his hematological indices were normal. However, he had a persistent slight elevation of fetal hemoglobin level. His mother and his brother were heterozygous for Hb D Punjab; his father had Hb CoSp trait. A sister did not have any abnormal hemoglobin. To show the exact molecular defect leading to the synthesis of Hb CoSp in this family, genomic DNA from the father was analyzed by hybridization with synthetic oligonucleotides. The results show that the Hb CoSp in the Batak family is due to a replacement of T by C in the TAA termination codon of the alpha sub(2)-globin gene changing it to CAA the codon for glutamine.