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Summary: Early diagnosis of congenital toxoplasmosis (CT) is necessary to prevent serious complications. The CT is diagnosed by the identification of the parasite in amniotic fluid during pregnancy or at birth by detection of antibodies synthesized by the fetus. The aim of this study was to determine the clinical and biological particularities of CT in a cohort of 11 cases observed in Tunisia and to evaluate the performance of the prenatal and neonatal diagnostic techniques that were used. In all patients, the presumed date of maternal contamination was determined based on the mother''s serological data. Neonatal serological screening included assays for immunoglobulins (Ig) G and IgM by enzyme-linked-immuno-sorbent assay (ELISA), IgM by immuno-sorbent-agglutination-assay (ISAGA), and comparison of the mother–baby immunological profile by western blot IgG and IgM. Seven out of the 11 cases had been diagnosed prenatally; only 3 (43%) had a positive polymerase chain reaction (PCR) test. Ten newborns out of 11 had serological criteria of fetal infection; western blot results were positive in all of them, ISAGA was positive in 2 and ELISA in none. The newborn who had a negative serology had been treated in utero. The date of positivity of the western blot test varied: 6 cases at birth, 2 at 12 days of life and 2 at 1month of life. The 2 patients who had positive ISAGA results had been contaminated during the 3rd trimester of gestation. [Copyright &y& Elsevier]

Abstract: Mucopolysaccharidosis type I (MPS I) is a lysosomal disease due to mutations in the gene encoding α-l-iduronidase (IDUA) leading to variable clinical phenotypes with progressive severe organomegaly, bone and neurological involvement in the most severe forms. The aim of our study was to propose in Tunisia a strategy of molecular and prenatal diagnosis of the MPS I. Population and methods: Our study was carried out on 8 MPS I patients recruited from different Tunisian regions and issued from 5 unrelated families. All the patients were offspring of consanguineous marriages. Results: The clinical and biological study led to diagnose 5 Hurler patients and 3 Hurler–Scheie patients. Three IDUA mutations were identified by molecular analysis within 6 different families: a novel mutation p.F602X and 2 already described mutations p.P533R and p.R628X. Discussion: MPS I is a heterogeneous disease characterized by variability of the phenotypes. The missense mutation p.P533R associated with the intermediate phenotype was the most frequent in the Tunisian but also in the Moroccan population. In Tunisia, the incidence of p.P533R mutation seems to be associated with the high frequency of consanguineous marriages. Conclusion: The identification of known MPS I mutations (p.P533R and p.R628X) and of the novel mutation p.F602X permits reliable genetic counselling of at-risk relatives and molecular prenatal diagnosis. [Copyright &y& Elsevier]