256 - Summary Incidence of hemoglobinopathies in a “non-endemic” area
Autor(s): M. Mercadanti, A. Caleffi, C. Monica
Issue: RIMeL - IJLaM, Vol. 3, N. 4, 2007 (MAF Servizi srl ed.)
Page(s): 256-261
Background. Hemoglobinopathies, i.e. hereditary disorders of haemoglobin synthesis, are the most frequent monogenic pathologies in the world and include a wide variety of clinical pictures of different seriousness. The aim of our work was to evaluate the incidence of he- moglobinopathies in the population relating to our laboratory, which is situated in a geographical area that is not considered as endemic for these pathologies, and to check if remarkable changes had occurred in 20 years’ time as to lead to new diagnostic routes. Methods. The study examined the work registers concerning the research for the screening of hemoglobinopathies, with regard to the years 1985, ’86, ’94, 2004 and 2005, where the patient’s private data, provenience (wards and health care centres located on-site), date and results of the analysis were reported for every analytic session. The screening was conducted by electrophoretic migration in the years 1985 and 1986, and by HPLC (Variant and Variant II Biorad) in the following years. The diagnosis of classical heterozygote -thalassemia was made for values of HbA2 ≥4.0%. The confirmation of HbS and HbC was obtained by means of the electrophoresis technique with alkaline and acid pH, and by the sickling test. As for the years 2004-2005, using the computer file reporting the birth date, we looked for the presence of multiple requests for the same patient carrying classical heterozygote -thalassemia. Results. Our results show a high incidence of classical heterozygote -thalassemia, with a maximum peak of 23.2% in the Eighties, decreasing to 11.3% in 2005. The record of structural variants progressively increased from 0.71% in 1985 to 5.1% in 2005. Hb S is the most frequent variant, followed by HbC. The cases of double heterozygosis S/C appeared in the last two years. The other variants included Hb Lepore, fast and variants in the years 1985 and 1995, whereas Hb Hasharon, OArabia, D Punjab, D Ibadan and J Oxford were present in 2005. In the Eighties the variants involved only Italian patients, while in the following years they mainly involved foreign patients, coming mostly from North Africa. The search for patients with multiple requests found out 16 subjects who repeated the survey twice and 2 patients with three requests; multiple requests principally occurred during hospital treatment. Conclusions. The high incidence of heterozygote -thalassemia and the constant increase in even unusual variants make it necessary for the laboratory of I diagnostic level to amplify the clinical and diagnostic knowledge, so as to record less common variants in the resident population and identify complex patterns given by the co-heritability of more defects. We believe that the identification of widespread variants, such as S and C, can be a competence of the I level, combining confirmation tests which are relatively easy and less expensive than molecular surveys (alkaline, acid migration, sickling test), whereas the most unusual cases or the complex patterns are remitted to the II level.