Incidence of β-thalassemia carrier on 1495 couples in preconceptional period.

This research, conducted on 1495 couples in preconceptional period, demonstrates how the study of globular resistance of erythrocytes (GRO) is not a first choice test and not useful as other more accurate tests to identify subjects with β-thalassemia trait. Instead, the complete blood count (CBC) and the evaluation of HbA, HbA2 and HbF by high pressure liquid chromatography (HPLC) are essential. Each couple arrived in our laboratory to screen for β thalassemia. In case of patients with positive (240) or doubtful (112) results, we studied β-globin gene. Of the 2990 subjects examined, we found 280 subjects with β-thalassemia trait (9.36%). During biochemical tests, among 112 subjects with doubtful--normal GRO or altered GRO--results, 40 of them resulted positive for the molecular analysis, while 72 of them did not show mutations in β-globin genes. The 2710 samples with non-carriers of β-thalassemia trait presented as mean evaluation of HbA2 2.6%, while the 280 subjects with β-thalassemia trait presented as mean evaluation of HbA2 4.8%. Molecular study showed that the β thalassemia phenotype is caused by a small number of mutations, whose regional distribution is typical. In the presence of thalassemic parameters in the CBC, the accurate and precise quantification of hemoglobin HbA2 is essential for the diagnosis of β-thalassemia trait. DNA mutation analysis provides the most effective way to detect primary gene mutations. The mutations identified in this work can be identified with a simple and inexpensive kit. This means, in economic terms, a significant savings for health spending.