The first Chinese case of unstable Hemoglobin Santa Ana detected by capillary electrophoresis: a case report and literature review

Figures & data

Figure 1. The CE result for the proband shows the Hb X fraction, which corresponds to the hemoglobin Santa Ana peak.

Figure 2. The result of Sanger sequencing. The arrow indicates the CTG > CCG mutation at codon 88 of the HBB gene previously reported as hemoglobin Santa Ana.

Table 1. Hematological and genotypic data of the family members.

Parameters	Proband	Father	Mother
Sex-age (years)	M-8	M-37	F-32
Hb (g/L)	94	164	125
RBC (10^12/L)	2.96	3.89	5.27
HCT (%)	32.5	49.1	37
MCV (fL)	109.7	93.3	95.2
MCH (pg)	31.8	31.2	32.3
MCHC (g/L)	290	334	339
Retic (%)	17.1	Not done	Not done
Hb A (%)	85.4	97.3	97.3
Hb A2(%)	3.9	2.7	2.7
Hb F (%)	4.1	0	0
Hb X (%)	6.6	0	0
HBA genotype	αα/αα	αα/αα	αα/αα
HBB genotype	β^CD88/β^N Hb Santa Ana/β^N	β^N/β^N	β^N/β^N

Hb: hemoglobin; RBC: red blood cell count; HCT: hematocrit; MCV: mean corpuscular volume; MCH: mean corpuscular hemoglobin; MCHC: mean corpuscular hemoglobin concentration; Retic: reticulocyte; Hb X: abnormal hemoglobin; β^N: normal HBB allele.

Table 2. Unstable hemoglobin variants migrated at zone 4 on the CE electrophoregram.

Variant name	Chain	Stability	Oxygen affinity	Trait% by CE	Clinical presentation of heterozygote
Hb Santa Ana	β	Unstable	Increased	6.6	Moderate anemia
Hb Köln	β	Unstable	Increased	4	Mild anemia
Hb Buenos Aires	β	Unstable	Increased	1	Compensated anemia
Hb E	β	Mildly unstable	Normal	15–30	Normal
Hb Agenogi	β	Mildly unstable	Slightly decreased	34–39	Normal
Hb Cleveland	β	Mildly unstable	Increased	31	Normal