Brazilian Journal of Genetics
On-line version ISSN 1678-4502
MIRANDA, Silvia R.P. et al. Hb Köln [a2b298(FG5) val-met] identified by DNA analysis in a Brazilian family. Braz. J. Genet. [online]. 1997, vol.20, n.4 ISSN 1678-4502. http://dx.doi.org/10.1590/S0100-84551997000400030.
Hb Köln was identified by DNA analysis in a Brazilian patient. A four-year old Brazilian female, with jaundice since birth, presented an abnormal band, between A2 and S, in hemoglobin electrophoresis on a cellulose acetate membrane, and a band with electrophoretic migration similar to Hb C on agar gel. Thermic instability and isopropanol precipitation tests were positive. Heinz bodies were observed in the patients peripheral blood. Sequencing of the three exons of the b globin gene detected a transition from G to A in the first position of codon 98. This alteration does not create or abolish any known restriction site. In this case, confirmation of the mutation was accomplished by allele-specific oligonucleotide hybridization, which is a simple and fast identification method when the clinical data and hematological and electrophoretic patterns are suggestive of Hb Köln.