IMPACT OF COINHERITANCE OF A-THALASSEMIA ON PHENOTYPE IN IRAQI KURDS WITH HOMOZYGOUS AND COMPOUND HETEROZYGOUS SEVERE Β -THALASSEMIA

  • DILAN JASIM KHALIL Lecturer, Scientific Research Center, College of the Sciences, University of Duhok, Duhok, Kurdistan Region, Iraq.
Keywords: β0 thalassemia, Coinheritance of α-thalassemia, α-gene deletions, Gap PCR

Abstract

https://doi.org/10.31386/dmj.2024.18.1.9

 

Background: Patients with homozygous or compound heterozygous β0 thalassemia may present either with thalassemia major or intermedia. This phenotypic variability is the consequence of several genetic modifiers in different populations. We aimed to assess the frequency and the impact of coinheritance of α-thalassemia on phenotype in Iraqi Kurds.

Methods: A total of 125 patients characterized as homozygous or compound heterozygous β0 thalassemia were recruited in thalassemia center Duhok. They were classified based on age of starting and the frequency of transfusion (thalassemia major or intermedia). All patients had their DNA extracted and Gap-PCR performed to identify 3 deletions namely: ‒α 3.7, ‒α 4.2, and ‒ ‒MED.  

Results: The patients had a median age of 12 years (Range 2.0-35), with 63 males and 62 females. 96 patient with thalassemia major and 29 with intermedia. The most frequent β-mutations were IVS-2.1 (G>A), Codon 44 (-C), codon 5 (-CT) and codon 8 (-AA). Gap PCR identified α-thalassemia in 9 patients (7.2%), including ‒α 3.7 /αα in 8 cases and ‒α 4.2/αα in one patient, while none had a double α-gene deletions. The frequency of α-thalassemia was higher in thalassemia intermedia at 13.8% compared to 5.2% in major. This difference was statistically insignificant (P=0.228).

Conclusions: The patients not appear to be a significant with homozygous or compound heterozygous β0 thalassemia. This may be attributed to low background frequency of α-thalassemia, it being mainly due to a single α-gene deletion. Further studies including more patients with extended β-genotypes and other genetic modifiers may be worthwhile.

Downloads

Download data is not yet available.

References

1. Al-Allawi N, Al Allawi S, Jalal SD. Genetic epidemiology of hemoglobinopathies among Iraqi Kurds. Journal of Community Genetics. 2021 Jan;12(1):5-14.
2. Jaing TH, Chang TY, Chen SH, Lin CW, Wen YC, Chiu CC. Molecular genetics of β-thalassemia: A narrative review. Medicine. 2021 Nov 11;100(45).
3. Taher AT, Musallam KM, Cappellini MD. β-Thalassemias. New England Journal of Medicine. 2021 Feb 25;384(8):727-43.
4. Origa R. β-Thalassemia. Genetics in Medicine. 2017 Jun 1;19(6):609-19.
5. Thein SL. Molecular basis of β thalassemia and potential therapeutic targets. Blood Cells, Molecules, and Diseases. 2018 May 1;70:54-65.
6. Verma IC, Kleanthous M, Saxena R, Fucharoen S, Winichagoon P, Raizuddin S, et al. Old JM. Multicenter study of the molecular basis of thalassemia intermedia in different ethnic populations. Hemoglobin. 2007 Jan 1;31(4):439-52.
7. Thein SL. Genetic modifiers of the β‐haemoglobinopathies. British journal of haematology. 2008 May;141(3): 357-66.
8. Al-Allawi NA, Jalal SD, Mohammad AM, Omer SQ, Markous RS. β-thalassemia intermedia in Northern Iraq: A single center experience. BioMed Research International. 2014 Feb 27; 2014.
9. Shamoon RP, Al-Allawi NA, Cappellini MD, Di Pierro E, Brancaleoni V, Granata F. Molecular basis of β-thalassemia intermedia in Erbil province of Iraqi Kurdistan. Hemoglobin. 2015 May 4;39(3):178-83.
10. Thuret I, Pondarré C, Loundou A, Steschenko D, Girot R, Bachir D, el al. Complications and treatment of patients with β-thalassemia in France: results of the National Registry. haematologica. 2010 May; 95(5):724.
11. Oron-Karni V, Filon D, Oppenheim A, Rund D. Rapid detection of the common Mediterranean α‐globin deletions/rearrangements using PCR. American journal of hematology. 1998 Aug; 58(4):306-10.
12. Al-Allawi NA, Badi AI, Imanian H, Nikzat N, Jubrael JM, Najmabadi H. Molecular characterization of α-thalassemia in the Dohuk region of Iraq. Hemoglobin. 2009 Jan 1;33 (1): 37-44.
13. Al-Allawi NA, Jalal SD, Rasheed NS, Bayat N, Imanian H, Najmabadi H,el al. The spectrum of α-thalassemia mutations in the Kurdish population of Northeastern Iraq. Hemoglobin. 2013 Feb 1; 37(1):56-64.
14. Shamoon RP. Molecular spectrum of α-thalassemia mutations in Erbil province of Iraqi Kurdistan. Molecular Biology Reports. 2020 Aug; 47(8):6067-71.
15. Piel FB, Weatherall DJ. The α-thalassemias. New England Journal of Medicine. 2014 Nov 13;371(20): 1908-16.
16. Neishabury M, Azarkeivan A, Oberkanins C, Esteghamat F, Amirizadeh N, Najmabadi H. Molecular mechanisms underlying thalassemia intermedia in Iran. Genetic testing. 2008 Dec 1;12(4):549-56.
17. Badens C, Joly P, Agouti I, Thuret I, Gonnet K, Fattoum S, el al. Variants in genetic modifiers of β-thalassemia can help to predict the major or intermedia type of the disease. haematologica. 2011 Nov;96(11):1712.
18. Jouini L, Sahli CA, Laaouini N, Ouali F, Youssef IB, Dakhlaoui B, et al. Association between clinical expression and molecular heterogeneity in β-thalassemia Tunisian patients. Molecular biology reports. 2013 Nov; 40:6205-12.
19. Danjou F, Francavilla M, Anni F, Satta S, Demartis FR, Perseu L, et al. A genetic score for the prediction of beta-thalassemia severity. Haematologica. 2015 Apr; 100(4):452.
20. Khan J, Ahmad N, Siraj S, Hoti N. Genetic determinants of β-thalassemia intermedia in Pakistan. Hemoglobin. 2015 Mar 4; 39(2):95-101.
21. Galanello R, Sanna S, Perseu L, Sollaino MC, Satta S, Lai ME, et al. Amelioration of Sardinian β0 thalassemia by genetic modifiers. Blood, The Journal of the American Society of Hematology. 2009 Oct 29; 114(18): 3935-7
22. Danjou F, Anni F, Perseu L, Satta S, Dessì C, Lai ME, et al. Genetic modifiers of β-thalassemia and clinical severity as assessed by age at first transfusion. Haematologica. 2012 Jul; 97(7):989.
23. Hariharan P, Gorivale M, Sawant P, Mehta P, Nadkarni A. Significance of genetic modifiers of hemoglobinopathies leading towards precision medicine. Scientific reports. 2021 Oct 22; 11(1):20906.
24. Faraon R, Daraghmah M, Samarah F, Srour MA. Molecular characterization of β-thalassemia intermedia in the West Bank, Palestine. BMC hematology. 2019 Dec;19 (1):1-9.
Published
2024-06-07
How to Cite
JASIM KHALIL, D. (2024). IMPACT OF COINHERITANCE OF A-THALASSEMIA ON PHENOTYPE IN IRAQI KURDS WITH HOMOZYGOUS AND COMPOUND HETEROZYGOUS SEVERE Β -THALASSEMIA. Duhok Medical Journal, 18(1), 77-86. Retrieved from https://dmj.uod.ac/index.php/dmj/article/view/302