Clinical and Molecular Characteristics of Non-Transfusion-Dependent Thalassemia in Kuwait

Abstract

Although not regularly transfused, patients with non-transfusion-dependent thalassemia (NTDT) are prone to iron overload and its complications. Their molecular, phenotypical and laboratory characteristics vary in different populations and there is a need to document local prevailing patterns. We have reviewed the records of our patients with NTDT in Kuwait and documented their clinical and molecular characteristics in addition to iron status [serum ferritin and liver magnetic resonance imaging (MRI) T2*], management and complications. There were 41 patients, made up of 20 with β-thalassemia intermedia (β-TI), 18 with Hb H (β4) disease and three with Hb E (HBB: c.79G > A)-β-thalassemia (Hb E-β-thal); their ages ranged from 3 to 36 years (mean 12.5 ± 7.7). While 18 (43.9%) had been transfused at least once, only three (7.3%) had been transfused on multiple occasions. Three patients had serum ferritin >500 ng/mL; while four of 38 had mild or moderate liver iron overload. Seven (35.0%) of the β-TI patients were managed with hydroxyurea (HU) with good response. Other complications included five patients with gallstones and one each of hypothyroidism and moyamoya. The most common mutations among the β-TI patients were IVS-II-1 (G > A) and IVS-I-6 (T > C), while among the Hb H patients, the Saudi α2-globin gene polyadenylation (polyA) (AATAAA > AATAAG) mutation was responsible for all cases either as homozygotes (61.1%) or compound heterozygotes with the α-thal-2 (–α^3.7) allele (33.3%). Although the pattern of NTDT in Kuwaiti patients is generally mild, there is a need to follow them to adulthood as the complications are cumulative and more prevalent in this group.

• β-Thalassemia intermedia (β-TI)
• Hb E-β-thalassemia (Hb E-β-thal)
• Hb H (β4)
• Kuwait
• non-transfusion-dependent thalassemia (NTDT)

Acknowledgements

The technical assistance of Mrs. Jalaja Sukumaran and Mr. Marcus D’Souza and of the Department of Pediatrics, Kuwait University, Jabriya, Kuwait is appreciated. The nurses and other members of the Pediatric Hematology Unit, Mubarak Al-Kabeer Hospital, Jabriya, contributed to the care of the patients reported here.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.