The genetics department is involved in research related to thalassemias, a group of genetically inherited blood disorders common in non-Caucasian populations, especially of Asian descent. The disease is caused by several distinct mutations in the globin genes and causes severe hematological symptoms including anemia. There is substantial heterogeneity in disease severity caused by the different globin gene mutations as well as other genetic modifiers, notably genetic variants which cause the persistence of fetal hemoglobin expression. Increased fetal hemoglobin expression compensates for defective beta globin chains and decreases disease severity.
We have two ongoing projects with the common goal of identifying disease modifying variants, The first is a sample of Thai thalassemia patients which have undergone two stages of genotyping, first in pools of individuals defined by disease severity followed by individual genotyping on the markers that showed different allele frequencies across pools. The second project, led by Dr. David Chui in the department of hematology, is a genome wide association study on a large cohort of Hong Kong Chinese families with beta thalassemia. Both projects have identified variants related to disease severity and persistence of fetal hemoglobin expression.