PMC8194298_01
High-performance liquid chromatography (HPLC): hemoglobin analysis of the patient. The percentages of HbA2 and HbF were 2.7 and 2.5%, respectively, and the abnormal peak was 41.7%, and HbA0 was 44.6% as determined by hemoglobin electrophoresis.
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F1
The Hb electrophoresis results showed that the levels of HbA2 were 2.7%, HbF 2.5%, and HbA0 44.6%, and an abnormal unknown peak of HbX (41.7%) (Figure 1) appeared at a retention time (RT) of 2.08 min. Therefore, the low MCV/MCH values, the normal HbA2 levels, and the clinical phenotype and red cell abnormalities were inconsistent with the Hb electrophoresis results.
Gap-PCR revealed the rightward deletion (-alpha3.7/alphaalpha) for the patient. N, normal; P, patient.
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F2
Gap-PCR revealed a heterozygote of the -alpha3.7 deletion (-alpha3.7/alphaalpha) (Figure 2) of the patient, while the RDB assay for the alpha2 gene mutations indicated no mutations.
DNA sequences of patient beta-globin genes. (A) HbJ-Bangkok (GGC   GAC) substitution at the beta-globin gene was observed (indicated by an arrow). (B) Part of the reverse DNA sequencing of the beta-globin gene showing the heterozygous mutation HBB: c.316-45G>C (indicated by an arrow).
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F3
Sanger sequencing of the beta-globin gene confirmed compound heterozygosity for HbJ-Bangkok (Figure 3A) and a mutation in the intron 2 region [IVS-II-806(G>C)] (Figure 3B).