Molecular Heterogeniety of β-Thalassemia in Karak District, Khyber Pakhtunkhwa, Pakistan

Abstract

β-Thalassemia (β-thal) is a monogenic disease characterized by mutations on the HBB gene, affecting the production of globin that results in hypochromic and microcytic anemia. The objective of this study was to determine the prevalence of six common β-thal mutations, their frequency, consanguinity in parents and inheritance pattern in patients of Karak region, Khyber Pakhunkhwa (KP) province, Pakistan. During the study, 200 peripheral blood samples were collected both from families having at least one transfusion dependent child and sporadic patients from different areas of karak region. Using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique, all samples were analyzed for the most common β-thalassemia mutations reported in Pakistani population. The most common mutations detected in karak region were frameshift codons (FSC) 8/9 (þG) (HBB: c.27_28insG), followed by IVS-I-5(G>C), FSC 5 (–CT) and Codon 15 (G>A). The present study hence showed differences with previous results from other regions of the Pashtun ethnic group, which demarcates the heterogeneity in mutations found in the Pashtun ethnicity. These observations may help in arranging counseling about disease recurrence in future, large scale mutation screening and PND not only for Kohat region but also the whole community of KP province. Such study could provide valuable information regarding thalassemia prevention like prenatal diagnosis (PND), genetic counseling and carrier screening for controlling the affected births in the population. Consanguinity, lack of awareness and non-availability of health facilities have thus contributed to the high occurrence of β-thal and miserable life of the patients.