The screening of Chinese cord blood for haemoglobinopathies.

The frequency of haemoglobinopathies among the Hong Kong Chinese newborn was examined by screening 932 consecutive cord blood samples by electrophoresis. The findings indicate that 49 (5.2%) had electrophoretic abnormalities, of which 39 (4.2%) demonstrated the presence of Hb Bart's. 14 of these 39 babies were re-investigated after 1 year and all were proven to carry the alpha-thalassaemia gene. This is the first study in which Chinese babies with Hb Bart's in cord blood had the diagnosis of alpha-thalassaemia trait confirmed in later life. 3 out of 4 other babies had different haemoglobin variants, namely Hb alpha Q, Hb J and Hb New York. 1 out of the 6 babies who had elevated A2 levels at birth was found to carry the beta-thalassaemia trait. None had a serious haemoglobinopathy.