Q: My HbA2 is 3.7%. It should be below 3.5% in a normal adult. What does my reading suggest?

A:The normal Hb A2 level in an adult is less than 3.5% and it is elevated (>4%) in b-thalassaemia trait. Your Hb A2 value lies in the indeterminate range. Beta thalassaemia trait (or heterozygous b-thal or thal minor or thal carrier or thal trait) is a clinically benign disorder. The importance lies in the fact that if both parents are carriers (i.e. carry one abnormal b-gene), an offspring may co-inherit a b-thalassaemia gene from both the parents making it homozygous resulting in a medically significant thalassaemia (b-thalassaemia major). Please get you spouse tested and, if normal, nothing needs be done and there is no problem. There are, however, very rare instances where a thal carrier may have normal Hb A2 level and such cases can be detected only by DNA analysis (so called Silent or near silent b-thalassaemia trait).