[Detection campaign for hemoglobinopathies and thalassemias among school children in northern Extremadura]

To detect carriers of thalassaemia and haemoglobin variants among the northern Extremadura school population.

The study was carried out in the Plasencia health service area, comprising about 120,000 people. All children between 4 and 15 years of age were offered to take part in the programme. The first-stage screen was mean corpuscular volule (MCV) measured in a Coulter STKS automatic counter. When low VCM was detected, ferritin estimation was carried out; if ferritin was normal, hemoglobin A2 was quantified. Haemoglobin electrophoresis at pH 8.4 was performed in all samples whatever the MCV, and patients were classified into the following groups: iron deficiency, beta-thalassaemia, Hb Lepore, structural haemoglobin variant, or atypical microcytosis.

Out of 22 schools from 20 towns, 2,818 children were studied, the participation reaching 75.48%. Lower than normal MCV was found in 162 children (5.74%), who were grouped as follows: thalassaemia, 15 cases (0.53%), Hb Lepore, 8 cases (0.28%), iron deficiency, 77 cases (2.73%), atypical microcytosis, 55 cases (1.95%), and structural variants 7 cases (0.24%). These variants were further identified as HbS (3), Hb Hofu (1), in natives, and HbC (3) in children from Morocco. Higher prevalence of anomalies was seen in some places: Riolobos, 1.5%, Galisteo, 2.5%, Jaraiz de la Vera, 3.02%; a significant group of Hb Lepore carriers was detected in this last town.

The prevalence of abnormalities seen in some small towns or villages grants this type of programmes as such places, which could be considered as isolated communities, might provide a number of high-risk couples.