Association of High-Altitude Polycythemia with JAK2V617F Mutation in Pakistani Population.

To assessthe prevalence of the JAK2V617F mutation in polycythemia patients living at high altitude. This was a cross-sectional study, conducted at the National Institute of Blood Diseasesand Bone Marrow Transplantation (NIBD-BMT), KarachifromJuly 2022 to July 2023. A total of 132 patients with polycythemia (male, hemoglobin ≥ 16.5 g/dl; female, hemoglobin ≥ 16 g/dl) were enrolled in the study. The patients were categorized on the basis of high and low altitude living and further categorization of those living at high-altitude was done on the basis of JAK2 positive and negative status and characteristics. Blood sample of each patient was collected in aseptic environment and sent to laboratory for complete blood count. PCR was used to detect JAK2V617F mutation. Data was analyzed by SPSS version 24. Among 132 polycythemia patients, 94 (71.2%) were high altitude residents whereas 38(28.7%) resided at non-high altitude. Out of 94(71.2%) patients of high altitude, 49(52.1%) harbored the JAK2V617F mutation whereas no mutation was identified in 45(48%) patients. The difference in gender distribution, median age, Hb, TLC, platelet count and ANC was statistically significant in the JAK2 positive group (p < 0.05). Moreover, palpable spleen and presence of ischemic heart was also found to be statistically significant in JAK 2 positive patients. Other characteristics such as hypertension, diabetes mellitus, smoking, and other symptoms (headache, body aches, chest pain, itching, abdominal pain, blurring of vision, burning soles, and cough) showed no significant differences between the two groups (p > 0.05). JAK2V617F mutation was observed in 52.1% ofpolycythemiapatients living at high altitude.