PESHAWAR: Researchers have found that people of Kho tribe in Chitral are developing resistance to cancer due to their DNA and genome amid high prevalence of risk factors for the disease in the region.

They have called for wide-ranging studies to ascertain if they have got immunity to fight the disease.

Many genes involved in cancer show natural selection trend in Kho tribe, possibly a biological mechanism to combat cancer disease, according to a five-year study conducted by Abdul Wali Khan University, Mardan.

Recently published in European Journal of Human Genetics, the study was meant to investigate genetic ancestry of Kho tribe by a team including Dr Asifullah Khan, Dr Shahid Aziz, Hizbullah Khan, Komal Zeb and Kiran Nigar of department of biochemistry, AWKUM.

It said that that Kho people might combat cancer burden due to their genome and physiology but on other hand, they stood exposed to the disease due to existence of causative factors in ecosystem.

Researchers fear prevalence of disease in the region, call for wide-ranging studies

The study was initiated in 2016. It involved 116 persons including men and women aging between 25 to 35 years. It was completed in collaboration with Prof Luca Pagani from University of Padova, Italy, Prof Shao-Qing Wen from Fudan University, Shanghai China, and Prof Qasim Ayub from Monash University, Malaysia.

It has recommended genome-wide association studies in large cohort from Kho, one of the major ethnic groups residing in Chitral predominantly, to know if the disease is prevalent among them or they have developed resistance at wider scale.

The findings of the study showed that genes of several people played role in development of immune responses, which might be an adaptation against pathogenic microbes’ infection. Cancer pathogenesis genes and underlie selection in Kho might reflect their adaptive response to increase exposure to ultraviolet radiation at high altitude in Hindu Kush mountainous range.

“Development of molecular anthropology section and departments in the universities are required to explore the genetics perspectives of mysterious ethnic groups residing in northern and north-western Pakistan,” said the study.

There is need to test many cancer patients from Kho people genome in comparison to normal Kho people. Furthermore, these areas are invaded in past by several empires that contributed to ethnic and cultural diversity.

The overall comparative population genetics analyses unveiled that the Kho people could trace a large proportion of their ancestry to those, who migrated from the Southern Siberian steppes during the second millennium BCE about 110 generations ago.

“Genes involved in muscular development, immune response and cancer pathogenesis undergone Darwinian natural selection, a process during which the populations acquire adaptive traits, having more likelihood for Kho people to survive and reproduce,” said the study.

These adaptive traits are inherited from individuals to their offsprings and over time such advantageous traits become common in population. According to it, their genome-scan showed trend of natural selection people for their muscular development as an adaptation to their lifestyle in the Hindu Kush Mountain valleys.

Likewise, specialised grants availability to researchers should be ensured because the genotype data generation for large number of samples during such projects needs to perform costly next generation DNA sequencing and array genotyping experiments.

“Additionally, huge data analysts are required for massive genomics data analyses and interpretation,” said the study.

Published in Dawn, March 14th, 2022