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Homozygous mild beta-thalassaemia promoter transversion −71 C>T HBB:c.-121 C>T
  1. Suha Mustafa Hassan1,
  2. Abdulhakim Alrawas2,
  3. Laila Al Khanbashi3 and
  4. Yasser Wali2,4
  1. 1Department of Hematology, Sultan Qaboos University, Muscat, Oman
  2. 2Department of Child Health, Sultan Qaboos University, Muscat, Oman
  3. 3Pediatrics, Government of Oman Ministry of Health, Muscat, Oman
  4. 4Department of Pediatrics, Faculty of Medicine, Alexandria University Faculty of Medicine, Alexandria, Egypt
  1. Correspondence to Dr Yasser Wali; yasser_wali{at}


Beta-thalassaemia is one of the most common genetic disorders worldwide, which is caused by absent or decreased synthesis of beta-globin chain subunits. Beta-thalassaemias are diverse groups of disease with a wide spectrum of clinical phenotypes. The clinical phenotypes can include asymptomatic forms of beta-thalassaemia minor, intermediate and severe transfusion dependent beta-thalassaemia major. Clinical severity varies depending on the underlying β globin gene mutation. There are a number of mild β-thalassaemia gene defects that could be referred as a ‘silent carrier’. Identifying the underlying molecular defect is essential to predict phenotype severity for optimal management, tailored treatment and improved quality of life.

We report the first identification of a homozygous point mutation located within the promoter region of the β‐globin gene at position −71 (C>T). The patient was a female child, who was referred to our clinic after she was found to have hypochromic microcytic anaemia with low haemoglobin (Hb) (67 g/L) and an Hb A2 level at the upper limit of the normal value (3.7%). This observation is a new example of homozygous mild β-thalassaemia with a borderline Hb A2 level, and illustrates a potential source of pitfall in the diagnosis of β-thalassaemia disease.

  • Haematology (incl blood transfusion)
  • Paediatrics
  • Genetics

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  • Contributors SMAL wrote the manuscript and did the genetic testing. YW and AA diagnosed the case, follwowed the clinical course, reviewed and edited the manuscript. LAK reviewed and edited the manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.