Y. Oshima et al., A PATIENT WITH A HEMOGLOBIN-VARIANT (HB J(LOME)) UNEXPECTEDLY DETECTED BY HPLC FOR GLYCATED HEMOGLOBIN (HB A(1C)), International journal of hematology, 68(3), 1998, pp. 317-321
A rare hemoglobin variant, Hb J(Lome), was identified by chance in a m
ale patient with diabetes mellitus (DM). The patient had no evidence o
f anemia or hemolysis. However, when his glycated hemoglobin (Hb A(1c)
) was examined by high-performance liquid chromatography (HPLC) to ass
ess the state of his DM, an abnormal Hb was unexpectedly detected on t
he chromatogram. The morphology of the red blood cells was normal. A f
ast-moving band as well as a normally moving Hb band, of roughly equal
intensities, were observed by cellulose acetate membrane electrophore
sis. The oxygen equilibrium curve was essentially normal (P-50 = 3.59
kPa). In other words, the ability of the patient's Hb to carry oxygen
was nearly the same as that of typical Hb A. The stability of his Hb i
n isopropanol was normal, and all the functions of his Kb that were te
sted were essentially normal. The identity of the abnormal Hb was fina
lly determined, by sequencing the globin gene, to be Hb J(Lome), which
is produced by a point mutation changing AAG to AAC at the 59th codon
in exon 2 of the Hb beta chain. As previously reported, replacing the
beta 59 lysine with asparagine does not affect the function of Hb or
the red blood cells. There have been only five documented cases of Hb
J(Lome) in Japan. Interestingly, all these cases are from Kyushu Islan
d. When an abnormal chromatogram for Hb A(1c) is unexpectedly obtained
, it is worthwhile searching for an abnormal Hb, even if there are no
signs that suggest its existence, such as anemia, hemolysis, erythrocy
tosis, or cyanosis. (C) 1998 Elsevier Science Ireland Ltd. All rights
reserved.