ADA2 deficiency: case report of a new phenotype and novel mutation in two sisters.

The objective of this paper is to: describe the phenotype compound heterozygote for mutations in CECR1 in two children. We describe the clinical and immunological phenotype, including the assessment of ADA2 activity, cytokine expression, interferon-stimulated and neutrophil-stimulated gene signatures, and the results of CECR1 sequencing. The first patient presented with intermittent fever, cutaneous vasculitis, myalgia and muscle inflammation on MRI leading to a provisional diagnosis of periarteritis nodosa. Subsequently, two cerebral lacunar lesions were identified following a brain stroke. Clinical features improved on anti-tumour necrosis factor therapy. The first patient's sister demonstrated early-onset, long-lasting anaemia with mild biological inflammation; at the ages of 3 and 5 years, she had presented 2 acute, transient neurological events with lacunar lesions on MRI. CECR1 sequencing identified both sisters to be compound heterozygous for a p.Tyr453Cys mutation and a previously undescribed deletion of exon 7. ADA2 activity was reduced by 50%. Neutrophil-stimulated genes were not overexpressed, but interferon-stimulated genes were. The expression of a panel of other cytokine transcripts was not significantly altered. In conclusion, searching for CECR1 mutation or assessing ADA2 activity should be considered in patients with an atypical presentation of inflammatory disease.

[Congenital myasthenic syndromes in childhood: Drug therapeutic strategies]. / Syndromes myasthéniques congénitaux de l'enfant : stratégies thérapeutiques médicamenteuses.

Congenital myasthenia syndromes (CMS) are a group of genetic disorders responsible for neuromuscular junction dysfunction. Usually beginning before 2 years of age, they are revealed by fatigability and muscle weakness, especially after stress, and often prevent the child's normal development. Over recent years, major advances in therapeutic strategies have been made following the discovery of numerous mutations responsible for CMS and the understanding of their pathogenic role. Here we report a pediatric CMS case caused by a mutation of the ɛ subunit of the acetylcholine receptor. The initial treatment with acetylcholinesterase inhibitor rapidly showed its limits in terms of both effectiveness and tolerance. The association with 3.4 diaminopyridine (DAP), a new drug available to treat such conditions, has transformed the motor outcome of our patient and allowed psychomotor development. In addition to 3.4 DAP, other molecules adapted to other types of CMS are now available. Three major groups of CMS can be distinguished depending on whether the deficit is at the presynaptic, synaptic, or postsynaptic level of the neuromuscular junction. Depending on the type of CMS, therapeutic management may include acetylcholinesterase inhibitors, 3.4 DAP, fluoxetine, quinidine sulfate, or ephedrine. With the case report, we provide a recent review of the literature on such new therapeutic options, their indications and restrictions, their mechanism of action, and prescription modalities. Knowing the precise CMS type and the appropriate therapeutic options available is essential for the proper management of such chronic and severe but relatively treatable childhood disorders.

Heterozygous CLCN1 mutations can modulate phenotype in sodium channel myotonia.

Nondystrophic myotonias are characterized by muscle stiffness triggered by voluntary movement. They are caused by mutations in either the CLCN1 gene in myotonia congenita or in the SCN4A gene in paramyotonia congenita and sodium channel myotonias. Clinical and electrophysiological phenotypes of these disorders have been well described. No concomitant mutations in both genes have been reported yet. We report five patients from three families showing myotonia with both chloride and sodium channel mutations. Their clinical and electrophysiological phenotypes did not fit with the phenotype known to be associated with the mutation initially found in SCN4A gene, which led us to screen and find an additional mutation in CLCN1 gene. Our electrophysiological and clinical observations suggest that heterozygous CLCN1 mutations can modify the clinical and electrophysiological expression of SCN4A mutation.

[N-methyl-D-aspartate receptor antibody encephalitis: value of immunomodulatory therapy]. / Encéphalite à anticorps anti-récepteurs N-méthyl-D-aspartate (NMDA-R) : place des immunomodulateurs.

INTRODUCTION: Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is little known to pediatricians and likely underdiagnosed. The child's vital and cognitive prognosis is at stake. The use of immunomodulatory drugs, such as rituximab has led to spectacular results, but many questions remain about its mode of action in this type of pathology. CASE REPORT: We report the case of a 6-year-old girl with no medical history, admitted for status epilepticus preceded by behavior symptoms and sleep disorders. Gradually, the child became bedridden, mute, and animated by predominantly orofacial dyskinesia. Examinations were normal (cerebrospinal fluid [CSF] analysis, brain MRI). The diagnosis was established by the presence of NMDA-R antibodies in the CSF. After exclusion of a tumor-associated syndrome, treatment was started initially by intravenous immunoglobulins, then by plasma exchange, and finally rituximab. The patient was cured with rituximab despite an unusually early recovery of the B-cell pool. DISCUSSION: Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is a severe but potentially reversible neurologic disorder only recently described, even in childhood. It may be reversible without sequelae if diagnosed and treated early. The use of immunomodulatory therapy, such as rituximab seemingly improves the outcome. Immunological monitoring is needed to better understand its mechanism of action in autoimmune diseases of the nervous system in childhood.

Basal ganglia neuroprotection with anticonvulsants after energy stress: a comparative study.

The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model provides a valuable paradigm of the energy deficiency disorders found in childhood. In such disorders, anticonvulsants may provide neuroprotection by modulating cellular energy consumption and by exerting favorable pleiotropic effects on neuronal survival. To verify such hypothesis, we tested the effects of levetiracetam, vigabatrin, gabapentine, pregabaline, tiagabine, clonazepam and lamotrigine on neuroprotection in the MPTP mouse model. The membrane dopamine transporter (DAT) density, which provides a reliable index of dopaminergic neurons survival in the basal ganglia, was assessed by semi-quantitative autoradiography of the striatum. Unlike all other anticonvulsants tested, lamotrigine provided a significant and dose-dependent neuroprotection in these experimental conditions. Lamotrigine, a widely used and well-tolerated molecule in children, could provide neuroprotection in various energy deficiency disorders.

MPTP intoxication in mice: a useful model of Leigh syndrome to study mitochondrial diseases in childhood.

The basal ganglia, which are interconnected in the striato-nigral dopaminergic network, are affected in several childhood diseases including Leigh syndrome (LS). LS is the most common mitochondrial disorder affecting children and usually arise from inhibition of the respiratory chain. This vulnerability is attributed to a particular susceptibility to energetic stress, with mitochondrial inhibition as a common pathogenic pathway. In this study we developed a LS model for neuroprotection trials in mice by using the complex I inhibitor MPTP. We first verified that MPTP significantly inhibits the mitochondrial complex I in the brain (p = 0.018). This model also reproduced the biochemical and pathological features of LS: MPTP increased plasmatic lactate levels (p = 0.023) and triggered basal ganglia degeneration, as evaluated through dopamine transporter (DAT) autoradiography, tyrosine hydroxylase (TH) immunohistochemistry, and dopamine dosage. Striatal DAT levels were markedly decreased after MPTP treatment (p = 0.003). TH immunoreactivity was reduced in the striatum and substantia nigra (p = 0.005), and striatal dopamine was significantly reduced (p < 0.01). Taken together, these results confirm that acute MPTP intoxication in young mice provides a reproducible pharmacological paradigm of LS, thus opening new avenues for neuroprotection research.

[Newborn asphyxia at term during delivery]. / Volume de recrutement, charge de travail et morbidité liés aux asphyxies per-partum à terme pour les services mobiles d'urgence et de réanimation (SMUR) pédiatriques.

UNLABELLED: Recruitment, work load and morbidity linked to newborn asphyxia during delivery at term: a study from Pediatric Mobile Intensive Care Units. OBJECTIVE: In a population of term neonates transported by the mobile intensive care units (MICU), we aimed to determine the incidence of neonates with anoxic-ischemic encephalopathy related to asphyxia, to analyze in this population the difficulties of management, and to try to identify which of these newborns require new therapeutic strategies. METHODS: This retrospective study was performed over a 2-year period (2000 and 2001) in 3 paediatric MICU from the Ile de France area. During this period, 7,648 infants were transported including 3,301 newborns of more than 36 weeks of gestational age and less than 72 hours of life. These neonates came from 73 different hospitals. Among these 3,301 infants, 237 neonates (124 boys and 113 girls) with anoxic-ischemic encephalopathy related to asphyxia were selected in the present study. Inclusion criteria were association of one obligatory criterion of fetal distress during delivery and at least one criterion of neonatal asphyxia or one criterion of anoxic-ischemic encephalopathy. Data were compiled and analyzed with Epidata package and Epi info package, respectively. RESULTS: These 237 neonates with anoxic-ischemic represented 12% of MICU activity at the same gestational and postnatal ages. The mean gestational age was 39.5 + 1.5 weeks. The mean birth weight was 3,188 + 559 g. More than 50% of these neonates were born in level I maternities. Fifty-three percent of the infants were born by caesarean section. Eighty-three percent of the neonates had an Apgar score at 1 minute <3. Eighty-eight percent of the neonates received resuscitation care at 5 minutes of life and 34% of these had an Apgar score at 10 minutes <5. In 50% of the cases, the MICUs arrived at the maternity of delivery within 1 h 45 min of life and transportation of the neonates was completed after 3 hours of life. The neonates were transported to an intensive care unit in 88% of the cases (half to a polyvalent intensive care unit and half to a neonatal intensive care unit). Forty-four percent of transported neonates had no encephalopathy, 30% had a severe encephalopathy or seizures, 27% had multiple organ failure. Mortality reached 28% and encephalopathy accounted for two thirds of these deaths. Neonates who arrived in pediatric care units after 3 hours of life had more severe morbidity than neonates who arrived before 3 hours of life. CONCLUSION: Pediatric MICUs transport the most severely affected neonates. The initial clinical state is critical, and systemic and neurological complications are frequent and severe. Calls to the MICU should be made earlier in order to enable a better impact of new neuroprotective strategies.