Molecular Heterogeneity of β-Thalassemia in the Kohat Region, Khyber Pakhtunkhwa Province, Pakistan.

The present study was intended to report the incidence of the most frequently occurring β-thalassemia (β-thal) mutations in the Kohat region [Khyber Pakhtunkhwa (KP) Province, Pakistan], their inheritance pattern in patients, and consanguinity in the parents. Moreover, this study could provide valuable information regarding thalassemia diagnoses such as prenatal diagnosis (PND), genetic counseling and carrier screening for controlling the affected births in the population. During this study, 160 peripheral blood samples of affected patients, their parents and siblings were collected from 25 discrete families having at least one child needing regular blood transfusions from different areas of the Kohat region. β-Thalassemia mutations found in the population were screened via the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). A total of 320 alleles was evaluated for the presence of six β-thal mutations. Of these six β-thal mutations, the frameshift codons (FSC) 8/9 (+G) (HBB: c.27_28insG) was found to be the most frequent in the studied population, and more interestingly, followed by IVS-I-5 (G>C) (HBB: c.92+5G>C) and FSC 5 (-CT) (HBB: c.17_18delCT). The findings of the present study show differences with previous results from other regions of the Pashtun population, which demarcates the heterogeneity in mutations found in the Pashtun ethnicity. These observations may help in implementing parental meetings about disease recurrence in future, large scale mutation screening and PND for the population of the Kohat region and also the whole Pashtun ethnicity.