10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 4 2013 (October - December) The inherited diseases of hemoglobin have remarkable phenotypic variability because of genetic modifiers necessitating medical intervention at various stages of disease. Genotype–phenotype relationship is crucial in this regard. So three year retrospective study of biochemical pattern of Hemoglobinopathies and Thalassemias and their clinical manifestations was done in a cohort of 689 patients in a tertiary care hospital. The highest incidence was Sickle cell disease (15.8%) followed by Sickle cell trait (13.1%), Thalassemia minor (11.8%), HbS/β-thalassemia (5.7%), Thalassemia major (1.6%). Less frequent were HbH disease, HPFH, Thalassemia intermedia, HbE, HbS/HbD, HbE/β-thalassemia, HbS/HPFH, HbD/β-thalassemia, HPFH/β-thalassemia, δβ trait and HbQ. Males had significantly higher incidence (55.2%). Thalassemia major had reduced HbA2 (1.9%). HbAS/α-thalassemia had higher mean age and low HbS as compared to Sickle cell trait. HbS/β lessThan sup greaterThan 0 lessThan /sup greaterThan -thalassemia had lower mean age and higher HbA2, HbS than HbS/β lessThan sup greaterThan + lessThan /sup greaterThan -thalassemia, corresponding with severity of disease. To conclude biochemical characterisation closely correlates with the clinical phenotype enabling correct diagnosis and avoids unnecessary investigations. PRISCILLA CHANDRAN, MANCHUKONDA SHIVA LAXMI, B. YADAGIRI, M.NOORJAHAN AND M.NAGESHWAR RAO Hemoglobinopathies, Thalassemia, Biochemical characterisation, HPLC. 1234-1242