Molecular Characterization of β-Thalassemia Mutations Via the Amplification Refractory Mutation System-Polymerase Chain Reaction Method at the North Waziristan Agency, Pakistan

Frequencies of Beta Thalassemia Mutations Show Different Pattern in Bannu Region than Other Parts of Pashtun Population in Khyber Pakhtunkhwa Province Pakistan

PURPOSE

β-Thalassemia arises as result of mutations in HBB gene, influencing the globin production which results in hypochromic and microcytic anaemia. The present study was aimed to investigate the occurrence of six common β-thal mutations, its inheritance pattern, frequency, and consanguinity in parents of Bannu region Khyber Pakhtunkhwa (KP) province, Pakistan. Conducting such studies may impart important information about thalassemia prevention like prenatal diagnosis (PND), carrier screening and genetic counselling which may be helpful in controlling the suspected births.

METHODS

During the study, 250 blood samples were retrieved from different families comprising of one transfusion dependent child and sporadic patients from different areas of Bannu region. The collected blood samples were investigated to see if there is any common mutations which may trigger β-Thalassemia employing amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) approach.

RESULTS

Amongst the studied mutation in District Bannu, frame shift codons (FSC) 8/9 (+ G) (HBB: c.27_28insG) was observed to be the most common mutation followed by Codons 41/42 (- TTCT), IVS-I-5(G > C) and FSC 5 (- CT) having frequencies of 42, 26, 19 and 13 respectively. The results obtained by the present study were found different from previous studies demonstrated from other Pashtun regions of KP, showing heterogeneity in frequencies of known mutations.

CONCLUSION

These observations may help in implementing parental meetings about disease recurrence in future, large scale mutation screening, and prenatal diagnosis in the whole Pashtun ethnicity including District Bannu.

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.