A novel sickle hemoglobin: hemoglobin S-south end.
Sickle hemoglobin (Hb S; beta Glu6Val) is due to an A<T transversion in codon 6 of the beta-globin gene. Several Hb S variants have both the Hb S mutation plus another mutation in the same beta-globin gene. Some of these variant hemoglobins can lead to sickle cell disease even in the simple heterozygote. Moreover, some variant hemoglobins mimic Hb A, S, or C on one or several clinical laboratory diagnostic tools, thus making their correct identification potentially problematic. The authors report a novel Hb S variant hemoglobin, Hb S-South End (beta Glu6Val, GAG>GTG; beta Lys132Asn, AAA>AAC). When present alone, the beta Lys132Asn mutation has low oxygen affinity. Therefore, this mutation may enhance the polymerization of the Hb S variant. Furthermore, the variant hemoglobin mimics Hb A on high-pressure liquid chromatography, and its identity is not easily diagnosed. A succinct review of variant sickle hemoglobins is also presented.
Luo
Hong-Yuan
HY
Hemoglobin Diagnostic Reference Laboratory, Boston Medical Center, Boston, Massachusetts, USA.
Adewoye
Adeboye H
AH
Eung
Shawn H
SH
Skelton
Timothy P
TP
Quillen
Karen
K
McMahon
Lillian
L
Steinberg
Martin H
MH
Chui
David H K
DH
D000328:Adult; D000755:Anemia, Sickle Cell / Q000175:diagnosis / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D019281:Dimerization; D005260:Female; D005914:Globins / Q000235:genetics; D006451:Hemoglobin, Sickle / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D020125:Mutation, Missense; D010100:Oxygen / Q000378:metabolism; D017354:Point Mutation
D006451:Hemoglobin, Sickle; C494159:hemoglobin S-south end; D005914:Globins; D010100:Oxygen