Eleven Cases of Hb J-Paris-I [: c.38C>A (or )]: A Stable α Chain Variant Elutes in the P3 Window on High-Performance Liquid Chromatography.

Hb J-Paris-I [: c.38C>A (or )] is a stable fast-moving hemoglobin (Hb) that elutes in the P3 window on high performance liquid chromatography (HPLC). The mutation can happen on either the α1- or α2-globin gene. Codon 12 changes from GC to GC to replace the alanine amino acid with aspartic acid. This change is external with no clinical significance. The elution in the P3 wave on HPLC can interfere with the glycated Hb assay by HPLC. In this study, data of 11 cases of Hb J-Paris-I were thoroughly presented. The majority of the cases were of Indian ethnicity. The mean value of Hb J-Paris-I on HPLC was 26.7 ± 2.0%. The retention time (RT) was 1.75 ± 0.03 min. The isoelectric focusing (IEF) mean value was -5.6 (range -6.1 to -4.9). Hb A was consistently reduced to 1.8 ± 0.3%. A fraction of 0.8% corresponding to the Hb A-J-Paris-I (αδ) is likely to be concealed within the A peak of Hb A on HPLC. Interestingly, two cases were associated with two different polymorphisms [: c.-24C>G or Cap +14 (C>G) and : c.*136A>G polymorphism] without apparent effect on the variant expression.