HB KOLN [ALPHA(2)BETA(2)98(FG5) VAL-MET] IDENTIFIED BY DNA ANALYSIS IN A BRAZILIAN FAMILY

Hb Koln was identified by DNA analysis in a Brazilian patient. A four- year old Brazilian female, with jaundice since birth, presented an abn ormal band, between A(2) and S, in hemoglobin electrophoresis on a cel lulose acetate membrane, and a band with electrophoretic migration sim ilar to Hb C on agar gel. Thermic instability and isopropanol precipit ation tests were positive. Heinz bodies were observed in the patient's peripheral blood. Sequencing of the three exons of the beta globin ge ne detected a transition from G to A in the first position of codon 98 . This alteration does not create or abolish any known restriction sit e. In this case, confirmation of the mutation was accomplished by alle le-specific oligonucleotide hybridization, which is a simple and fast identification method when the clinical data and hematological and ele ctrophoretic patterns are suggestive of Hb Koln.