Hb Chapel Hill or Alpha2 74(EF3) Asp>Gly, a mildly unstable variant found in a Chinese family

Figures & data

Figure 1. The family pedigree: the proband (II-4) is marked with an arrow.

Figure 2. Electropherograms of hemoglobin A plus hemoglobin Chapel Hill, the peaks from left to right being Hb A, Hb Chapel Hill (α^{Chapel Hill} ₂β₂) (zone 7), Hb A₂, and Hb Chapel Hill₂ (α^{Chapel Hill} ₂δ₂) (zone 1).

Figure 3. DNA sequencing analysis showing the mutation of HBA2: c.224A > G on the α2 gene. (arrow indicates heterozygous HBA2: c. 224A > G mutation).

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

Parameters	father	mother	brother	Proband	sister
Sex-age	M-58	F-57	M-34	F-33	F-33
Hb (g/dL)	15.7	15.1	16.9	12.2	14.6
RBC (10^12/L)	5.01	5.08	5.52	4.71	4.91
MCV (fl)	94.1	87.1	88.7	77.8	87.1
MCH (pg)	31.2	29.8	30	25.9	29.7
Hb Chapel Hill (%)	20.2	-	-	18.4	19.9
Hb A2 (%)	1.9	2.6	2.7	2.1	2
Hb A2 variant (%)	0.4	-	-	0.5	0.4
FER (ng/mL)	131.9	186.67	194.81	16.97	23.88
HBA Genotype	α^Chapel Hillα/αα	αα/αα	αα/αα	α^Chapel Hillα/αα	α^Chapel Hillα/αα
HBΒ Genotype	βN/βN	βN/βN	βN/βN	βN/βN	βN/βN

FER: ferritin.