Blood group prevalence has huge importance in medical field since it plays an important role in blood transfusion, organ transplantation 11, evolution, and genetics research. It is also associated with various diseases including cardiovascular diseases 12, erythroblastosis in neonates, duodenal ulcer and diabetes 13,14,15. In this study, frequency distribution of ABO and Rh blood group among the people of Safdarabad and Faisalabad cities of Pakistan was estimated. The blood group phenotypes among the people of Safdarabad and Faisalabad appeared to be in the B > O > A > AB and O > B > A > AB orders respectively. Among ABO groups, the AB blood group has been reported the least prevalent group all over the world while O blood group is considered the most common blood group in most of the areas. In the current study, amongst the people of Faisalabad, the blood group O was found the most prevailing blood group while blood group B was found the most frequent in Safdarabad city. The findings of O blood group as the most common in Faisalabad city is in accordance with the reported studies of other countries like Saudi Arabia 16, Bahrain 17, Iran 18, India 19, Nigeria 20 and Bangladesh 21. The findings of Safdarabad is also in compliance with the study conducted in Punjab province of India 6. Findings in both Faisalabad and Safdarabad are different from the reported studies of Turkey 22 and Palestine 23, where blood group A appeared to be the most prevalent blood group. These variations in the blood group frequency may be due to external environment, geographical differences, and genetic factors.
Although, these variations are when compared on national level, it exhibits a heterogeneity among different cities of Pakistan. These differences can be due to geographical environment, ethnic groups and more specifically due to different sample size. Study from Dir upper25, Peshawar26, Sakardu8 and Dir lower27 shows that blood group A was the commonest group in those areas. Other studies from twin cities Islamabad and Rawalpindi28, Gujranwala29, Lahore30, Mirpur31 and Multan32 reflects the same result like presented in this study of Safdarabad. The current findings of Faisalabad city where blood group O is found the most common is in agreement with the studies conducted in Multan32, Karachi33, and Gujrat34 cities (Table 3).
The frequency of Rh (D) positive and negative phenotypes was 90% and 10% respectively for Safdarabad and 81.01% and 18.99% for Faisalabad. Other studies available in literature archive also indicated somewhat similar pattern in various cities of Pakistan (Table 3) and in different other countries (Table 3).