Ko Tsang-ming explains that there are two types of thalassemia: alpha and beta. If both parents are carriers of the same type of thalassemia, there is a 25 % chance that their child will suffer from a severe form of anemia. Thalassemia leads to impaired hemoglobin synthesis and hemoglobin deficiency, and adversely affects the oxygen-carrying capacity of the hemoglobin in the blood, necessitating periodic blood transfusions or bone marrow transplants.
柯滄銘指出，海洋性貧血又分為甲型和乙型，夫妻如果為同型的帶因者，下一代將有四分之一的機率罹患重型貧血，不但影響血紅蛋白的合成，缺少血紅蛋白，連帶地血紅素和血液攜帶氧的能力也會受影響，必須仰賴定期輸血或骨髓移植治療。