Novel interactions of two α-Hb variants with SEA deletion α⁰-thalassemia: hematological and molecular analyses

Figures & data

Figure 1. Hemoglobin analysis of the two patients (P1 and P2) who were respectively compound heterozygotes for Hb G-Georgia/α⁰-thalassemia and Hb Nakhon Ratchasima/α⁰-thalassemia using automated HPLC and CE systems. The separated profiles of Hb G-Georgia, Hb Nakhon Ratchasima (NR), Hb A, Hb A₂ and Hb A₂NR are depicted.

Figure 2. Identification of the Hb G-Georgia and Hb Nakhon Ratchasima mutations by PCR-RFLP assays using MspI and SalI digestion, respectively. The locations and orientations of primers αG39 and C3 and the size of amplified α2-globin gene fragment (883 bp) are illustrated. The sizes of MspI and SalI-digested fragments specific for α^G-Georgia (258 bp) and α^{Nakhon Ratchasima} (539 bp and 344 bp) and their normal counterparts are indicated. In agarose gel electrophoresis, M represents the GeneRuler 50 bp DNA ladders. 1 and 4: undigested amplified DNA, 2: MspI-digested amplified DNA of normal subject, 3: MspI-digested amplified DNA of the P1 with Hb G-Georgia/α⁰-thalassemia, 5: SalI-digested amplified DNA of normal subject, 6: SalI-digested amplified DNA of the P2 with Hb Nakhon Ratchasima/α⁰-thalassemia.

Table 1. Hematological data and globin genotypes of Thai patients with Hb G-Georgia/α⁰-thalassemia and Hb Nakhon Ratchasima/α⁰-thalassemia as compared to other α-globin chain variants with similar genotypes including Hbs Thailand [5], Phnom Penh [5] and Hekinan [11] previously found in our laboratory. GG = Hb G-Georgia, NR = Hb Nakhon Ratchasima.

Parameters	P1:Hb G-Georgia (This study)	P2:Hb Nakhon Ratchasima (This study)	Hb Thailand [5] (n = 1)	Hb Phnom Penh [5] (n = 1)	Hb Hekinan [11] (n = 3)
CBC
Rbc (×10^12/l)	6.2	2.3	6.8	5.0	5.9 ± 0.4
Hb (g/dl)	11.4	5.3	15.2	9.9	12.6 ± 0.4
Hct (%)	36.1	16.0	49.0	30.0	38.9 ± 1.0
MCV (fl)	57.8	69.0	72.0	60.7	65.6 ± 3.4
MCH (pg)	18.2	22.7	22.4	19.8	21.3 ± 4.4
MCHC (g/dl)	31.6	33.1	31.1	32.6	32.5 ± 1.0
RDW (%)	19.1	na	15.0	16.3	na
Hb analysis
HbA2 (%)	1.9^a	1.6^b	1.4	1.6	2.2 ± 0.2
Hb variant (%)	44.9^a	33.4^b	40.5	98.2	97.2 ± 0.7^a
Hb A2-variant (%)	un-detected^a	1.4^b	0.7	0.2	na
Globin genotype
α-genotype	α^GGα/–^SEA	α^NRα/–^SEA	αα^Thailand/–^SEA	αα^Phnom Penh/–^SEA	α^Hekinanα/–^SEA
β-genotype	β^A/β^A	β^A/β^A	β^A/β^A	β^A/β^A	β^A/β^A

^aDetermined using CE.

^bDetermined using HPLC.

na: not available.

Singha K, Srivorakun H, Fucharoen G, et al. Association of Hb Thailand [alpha56(E5)Lys-->Thr] and Hb Phnom Penh [alpha117(GH5)-Ile-alpha118(H1)] with alpha(0)-thalassemia: molecular and hematological features and differential diagnosis. Hemoglobin. 2013;37:37–47. doi: 10.3109/03630269.2012.747964

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Fucharoen S, Changtrakun Y, Ratanasiri T, et al. Complex interaction of Hb Hekinan [alpha27(B8) Glu-Asp] and Hb E [beta26(B8) Glu-Lys] with a deletional alpha-thalassemia 1 in a Thai family. Eur J Haematol. 2003;70:304–309. doi: 10.1034/j.1600-0609.2003.00049.x

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