Hb Koln [β98(FG5) [GTG → ATG, Val → Met]: the first report from India.

BACKGROUND

The group of unstable hemoglobins are associated with congenital non-spherocytic hemolytic anemia due to instability of the hemoglobin molecule. They often lead to formation of the characteristic inclusion bodies or Heinz bodies.

AIM

To identity the cause of mild anemia, reticulocytosis, and hepatosplenomegly in a case of non-spherocytic hemolytic anemia.

MATERIALS AND METHODS

A 34-year-old female patient originating from Maharashtra, western India presented with mild anemia and jaundice which had persisted since childhood. Investigations included a complete blood count, screening for red cell membrane protein defects, Hb analysis by high-performance liquid chromatography (HPLC) and cellulose acetate electrophoresis (pH 8.9), heat instability test and DNA sequencing.

RESULTS

Hemoglobin analysis by HPLC showed an abnormal peak in the Hb C window (9.8%) with a retention time of 4.90 minutes. Cellulose acetate electrophoresis (pH 8.9) showed a slow moving band (6.15%) between Hb A2 and Hb S. The heat instability test was positive. DNA analysis of α globin genes showed absence of both deletional and non- deletional α thalassemia. DNA sequencing of the β globin gene revealed heterozygosity for a mutation at codon 98 [GTG → ATG, Val → Met], which gives rise to Hb-Koln.

CONCLUSION

Hb Koln is the commonest unstable Hb variant reported from many populations in the world. However, this is the first report of this unstable Hb variant from India.