Yonsei Med J.  2017 May;58(3):665-667. 10.3349/ymj.2017.58.3.665.

Hb Heathrow [β103(G5)Phe→Leu], a First Report in an Asian Patient with Erythrocytosis

• Shin SY
• Kim HY
• Kim HJ
• Kim HG

• KMID: 2419129
• DOI: http://doi.org/10.3349/ymj.2017.58.3.665

Abstract

Congenital erythrocytosis (CE) is a rare and heterogeneous disease. The high oxygen affinity hemoglobin (Hb) variants are the most common cause of CE. Herein, we report a Korean patient with isolated erythrocytosis. A 25-year-old man was referred to our hospital for evaluation of high Hb level (Hb 20.4 g/dL, hematocrit 58%, reticulocyte count 2.90%, white blood cell count 6.83×10⁹/L, and platelet count 195×10⁹/L). Bone marrow biopsy revealed normocellular marrow without myeloproliferative features. JAK2 (V617F, exon 12), CALR (exon 9), and MPL W515K/L mutations were not detected. P₅₀ (partial pressure at which Hb is half saturated with oxygen), which is an indicator of left-shift of oxygen dissociation curve (high oxygen affinity state), was 14.3 mm Hg (reference value 22.6-29.4 mm Hg). He was suspected to have CE. Mutation analysis of the HBB gene revealed the known Hb variant, Hb Heathrow [β103(G5)Phe→Leu]. This is the first report of Hb Heathrow in Asian.

Keyword

Hemoglobin variant; Hb heathrow; erythrocytosis

MeSH Terms

Adult
Biopsy
Bone Marrow/pathology
*DNA Mutational Analysis
Exons/genetics
Frameshift Mutation
Hemoglobins, Abnormal/*genetics/isolation & purification/metabolism
Humans
Janus Kinase 2
Male
Mutation
Oxygen/metabolism
Polycythemia/blood/*genetics
Hemoglobins, Abnormal
Janus Kinase 2
Oxygen

Figure

• 

  Fig. 1 Peripheral blood, bone marrow section, and HBB sequencing analysis results. (A) Erythrocytosis (peripheral blood, Wright-Giemsa, ×400) and (B) normocellular marrow without myeloproliferative features are noted (hematoxylin and eosin stain, ×100). (C) DNA sequencing of hemoglobin beta gene identified a heterozygous mutation at position 310, resulting in replacement of a phenylalanine by a leucine residue [β103(G5)Phe→Leu, NM_000518.4:c.310T>C (p.Phe104Leu)]. The arrow indicates the 310th nucleotide. HBB, beta-globin gene.

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