Pediatric Neurotuberculosis: A cases series and review of the literature.

Neurotuberculosis or central nervous system tuberculosis is a form of tuberculous infection that affects any part of the nervous system. Although it is more frequent in adults, pediatric cases have been reported in endemic countries and it is potentially a deadly affection. Therefore, any unusual neurological manifestation in a formerly healthy child, independently of their vaccination status, must bring suspicion of CNS tuberculosis among other diagnoses. We report four cases of pediatric neurotuberculosis with various clinical presentations and outcome and a brief review of the litterature. We conclude that clinical manifestations of pediatric neurotuberculosis are extremely variable and could be misleading. Extra-neurological sites are a key element for diagnosis especially in the pediatric population. A diagnosis and clinical outcome score, especially designed for children might help personalize the therapeutic approach and outcome measures.

Alpha-mannosidosis in Tunisian consanguineous families: Potential involvement of variants in GHR and SLC19A3 genes in the variable expressivity of cognitive impairment.

Alpha-Mannosidosis (AM) is an ultra-rare storage disorder caused by a deficiency of lysosomal alpha-mannosidase encoded by the MAN2B1 gene. Clinical presentation of AM includes mental retardation, recurrent infections, hearing loss, dysmorphic features, and motor dysfunctions. AM has never been reported in Tunisia. We report here the clinical and genetic study of six patients from two Tunisian families with AM. The AM diagnosis was confirmed by an enzymatic activity assay. Genetic investigation was conducted by Sanger sequencing of the mutational hotspots for the first family and by ES analysis for the second one. In the first family, a frameshift duplication p.(Ser802GlnfsTer129) was identified in the MAN2B1 gene. For the second family, ES analysis led to the identification of a missense mutation p.(Arg229Trp) in the MAN2B1 gene in four affected family members. The p.(Ser802GlnfsTer129) mutation induces a premature termination codon which may trigger RNA degradation by the NMD system. The decrease in the levels of MAN2B1 synthesis could explain the severe phenotype observed in the index case. According to the literature, the p.(Arg229Trp) missense variant does not have an impact on MAN2B1 maturation and transportation, which correlates with a moderate clinical sub-type. To explain the intra-familial variability of cognitive impairment, exome analysis allowed the identification of two likely pathogenic variants in GHR and SLC19A3 genes potentially associated to cognitive decline. The present study raises awareness about underdiagnosis of AM in the region that deprives patients from accessing adequate care. Indeed, early diagnosis is critical in order to prevent disease progression and to propose enzyme replacement therapy.

X-linked Adrenoleukodystrophy, The Tunisian Experience.

BACKGROUND: X-linked adrenoleukodystrophy is a genetic disease affecting the degradation of very long chain fatty acids. This study aims to describe the clinical phenotype and biochemical feature of Tunisian patients; it also seeks to describe recognition of pattern analysis on the level of very long chain fatty acids in plasma for the visual discrimination of X-linked patients from a healthy group. METHODS: During the last 21 years, 19 patients were diagnosed with X-linked adrenoleukodystrophy based on the clinical features combined with the area percentage of hexacosanoic acid (C26:0) as well as the ratio of C26:0 and lignoceric acid (C24:0) relative to behenic acid (C22:0) by gas chromatography. For the biochemical diagnosis of X-ALD with better accuracy, it has been desired to transform the numerical values of these biochemical markers into visually discriminating patterns. RESULTS: The clinical features of 19 patients aged between 4 to 47 years were classified into cerebral form (57.8%), adrenomyeloneuropathic (26.3%), and a few patients were asymptomatic. The ratio C24:0/C22:0 ranged from 1.12 to 2.41 (normal value: 0.46 - 0.9) and C26:0/C22:0 ratio ranged from 0.03 to 0.36 (normal value: 0.003 - 0.009). The concentration of fatty acids with 22 or more carbons in body fluid did not change with age in control subjects and patients. For the visual diagnostic of patients, the Scatter plot was a reliable method for the diagnostic patterns of very long chain fatty acids of patients with X-linked adrenoleukodystrophy disorders. CONCLUSIONS: The incidence of X-linked adrenoleukodystrophy disorders is under diagnosed in Tunisia. The diagnosis was confirmed by enzymatic activity study and molecular analysis but the analysis of very long chain fatty acids by gas chromatography remains a reliable tool for the diagnosis and early initiation of the treatment.

Clinical and Biochemical Profile of Tyrosinemia Type 1 in Tunisia.

BACKGROUND: Hereditary tyrosinemia type 1 (HT1) is an autosomal recessive disease caused by a defect of fumarylacetoacetate hydrolase. This study aimed to estimate the prevalence of HT1 in Tunisia and report its clinical, biochemical and genetic features. METHODS: During the last 25 years, 69 patients were diagnosed with HT1 based on clinical features and increased succinylacetone (SA) in blood and urine. SA was detected by GC-MS after oximation and quantified by a spectrophotometric method. Nine prenatal diagnoses for HT1 have been done and nine unrelated patients were screened for the hotspot IVS6-1(G-T) mutation using PCR. RESULTS: Using the Hardy-Weinberg formula, the incidence of HT1 was estimated at 1/14804 births in Tunisia. According to clinical form, 21 patients (30%) had the acute form and 48 patients (70%) had the chronic form. Mean plasma and urine SA were higher in the acute form (24 and 193 µmol/L vs. 9 and 90 µmol/L, respectively). Diagnosis of HT1 was done for 4 fetuses. The hotspot IVS6-1(G-T) mutation was found in six of nine explored patients. CONCLUSIONS: The incidence of HT1 is relatively high in Tunisia with a predominance of the chronic form. It is important to diagnose the disease as early as possible to prevent unfavorable issues. Prenatal diagnosis should be recommended to minimize the recurrence of the disease.