Neonatal screening for sickle cell anemia : Evaluation of the IEF protocol

Abstract

Background : The sickle cell anemia is a genetic disease with a recessive autosomal transmission, dominated by severe anemia, painful crises and big susceptibility to bacterial infections. The premature care of the homozygous (SS) is the best way to minimize the clinical severity and this passes by the neonatal screening. Several approaches had yet been developed. Aim : In our lab, eight years after the implementation of the neonatal screening of the sickle cell anemia, we try here to evaluate the technique used to detect this disease, the isoelectrofocusing analysis (IEF), and reveal the optimal conditions which allow detecting 100 % of the cases. Methods : This work was conducted on 210 newborns born at the maternity center, La Rabta. Two types of blood sampling were collected for every subject: a cord blood used for HPLC analysis and PCR / RFLP analysis and dried blood samples used in IEF followed by a confirmation by HPLC. Results : The HPLC revealed 10 samples among 210 tested ones, confirmed by the molecular method: 8 heterozygous (AS) and 2 heterozygous (AO), while the IEF analysis revealed only 3 cases of sickle cell trait, a homozygous S/S and a heterozygous (AO). Conclusion : The difference between the obtained results shows that homozygous (SS) detection cannot be missed by IEF analysis. Optimization has to be brought to this technique to ensure fully detection of the whole cases of βS carriers by concentrating samples.