Prenatal diagnosis of hemoglobinopathies in Tunisia: an 18 years of experience

• Published in: International journal of laboratory hematology Vol. 38; no. 3; pp. 223 - 232
• Main Authors: Ouali, F., Siala, H., Bibi, A., Hadj Fredj, S., Dakhlaoui, B., Othmani, R., Ouenniche, F., Zouari, F., Bouguerra, B., Rezigua, H., Fattoum, S., Messaoud, T.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-06-2016
• Subjects: amniocentesis; Anemia, Sickle Cell - diagnosis; Anemia, Sickle Cell - epidemiology; Anemia, Sickle Cell - genetics; beta-thalassemia; beta-Thalassemia - diagnosis; beta-Thalassemia - epidemiology; beta-Thalassemia - genetics; chorionic villus sampling; Female; Fetal Diseases - diagnosis; Fetal Diseases - epidemiology; Fetal Diseases - genetics; hemoglobinopathies; Humans; Male; Polymerase Chain Reaction; Pregnancy; Prenatal diagnosis; Prenatal Diagnosis - instrumentation; Prenatal Diagnosis - methods; Retrospective Studies; sickle cell disease; Tunisia; amniocentesis; Prenatal diagnosis; chorionic villus sampling; hemoglobinopathies; beta-thalassemia; sickle cell disease
• ISSN: 1751-5521; 1751-553X
• DOI: 10.1111/ijlh.12457

Summary
Hemoglobinopathies are the most common genetic disease in Tunisia with a total carrier prevalence of 4.48%.
Objective
The aim of this study was to report an 18‐year fully achieved experience of prenatal diagnosis (PND) of hemoglobinopathies (1994–2012) and to assess the impact of this prevention program.
Patient and methods
A total of 461 fetuses of 340 at‐risk couples have been the subject of PND for beta‐thalassemia major risk (41%), for sickle cell anemia risk (40.3%), for S/beta‐thal risk (14.7%). The remainder fetuses were at risk for a compound heterozygote hemoglobinopathies (S/O, O/beta‐thal, S/C….). Fetal DNA was studied by PCR procedure including the reverse dot‐blot technique and the amplification refractory mutation system and direct sequencing.
Results and discussion
Only 13.8% of the fetal samplings were conducted by chorionic villus sampling. The molecular result for beta‐thalassemia risk has shown 13 beta‐thal mutations, with two common: codon 39 (C>T) and IVS1‐110 (G>A). The last 3 years, STR study has permitted to reduce the problems of maternal cell contamination. Among the 461 tested fetuses, 121 were affected, and then the pregnancy was terminated except for 13 cases, because of religious considerations and this despite the abortion legality in Tunisia. The conducted PND is only about 30 PND per year corresponding essentially to the couples living in Tunis City and surrounding area. PND number has increased from 1994 to 2009. This evolution has brutally decreased after the Tunisian revolution (2010).
Conclusion
Although the good running of the PND, it covers only the Tunis city with low impact because it prevent apparition of only a mean of 7.3% of new cases. The reduced number of PND is not a technical inconvenience but rather a lack of a preventive program.