What are the key clinical features that differentiate alpha thalassaemia from beta thalassaemia in adults?

Key clinical features differentiating alpha thalassaemia from beta thalassaemia in adults:

• Alpha thalassaemia typically results from deletions of one or more alpha globin genes. Adults with one or two gene deletions are usually asymptomatic or have mild hypochromic microcytic anaemia without significant clinical symptoms. More severe forms, such as haemoglobin H disease (three alpha globin genes absent), can present with varying severity of anaemia, jaundice, and hepatosplenomegaly. In pregnancy, severe anaemia and haemolytic crises may occur due to oxidative stress or infection NICE CKS.
• Beta thalassaemia results from mutations affecting beta globin production. Adults with beta thalassaemia major often have severe anaemia requiring regular transfusions, iron overload complications, and endocrinopathies such as diabetes mellitus, hypothyroidism, and hypoparathyroidism. Beta thalassaemia trait carriers may have mild microcytic anaemia that can be confused with iron deficiency anaemia, necessitating careful iron studies NICE CKS.
• Beta thalassaemia is associated with increased risks during pregnancy including worsening anaemia, cardiomyopathy due to iron overload, and fetal growth restriction, requiring multidisciplinary management NICE CKS.
• Alpha thalassaemia carriers generally have normal pregnancy outcomes unless they have haemoglobin H disease, which can cause more severe complications NICE CKS.