Detection of Non-Deletional Αlpha Thalassaemia in Hospital Tengku Ampuan Rahimah, Klang, Malaysia

Abstract

Background: To date, more than 70 variants of non-deletional mutations associated with α-thalassaemia have been recognized and recorded, showcasing the diverse genetic manifestations of the condition. Objective: This study is to provide data on the non-deletional alpha (α) thalassaemia cases at Hospital Tengku Ampuan Rahimah (HTAR), Klang, Selangor and to compare the hematological parameters (Hb, RBC, MCH, MCV, MCHC) of non-deletional α thalassaemia with the deletional variant. Methods: This was a cross-sectional study involving data extraction from the HTAR hematology laboratory registry on confirmed thalassaemia cases via DNA analysis from January 2017 to December 2019. Hematological parameters were obtained from the laboratory database. Results: A total of 479 α thalassaemia cases were recruited, 98 (20.5%) were non-deletional type. Among these, 75 (76.5%) were heterozygous Hb CS, 17 (17.3%) heterozygous Hb Adana, 3 (3.1%) heterozygous Hb Quong Sze (QS) and 1 (1.0%) case each of compound heterozygous Hb Constant Spring (CS) and Hb Adana (αCSα/αCD59α), compound heterozygous Hb CS and -3.7kb deletion (αCSα /-α3.7) and compound heterozygous of Hb CS and SEA deletion (αCSα/--SEA). In the single and double gene mutated groups, there was no significant difference of hematological parameters between the deletional and non-deletional groups. Among the nondeletional variants, there was a significant association between Hb, MCH and MCHC parameters and the number of mutated α gene. Conclusion: The result can update the data of non-deletional α thalassaemia.

Keywords

• non-deletional mutation
• α thalassaemia
• hb constant spring
• hb adana
• hb quong sze