Epilepsy with faint capillary malformation or reticulated telangiectasia associated with mosaic AKT3 pathogenic variants

Capillary malformations (CMs) are the most common type of vascular anomalies, affecting around 0.3% of newborns. They are usually caused by somatic pathogenic variants in GNAQ or GNA11. PIK3CA and PIK3R1, part of the phosphoinositide 3-kinase-protein kinase B-mammalian target of rapamycin pathway, are mutated in fainter CMs such as diffuse CM with overgrowth and megalencephaly CM. In this study, we present two young patients with a CM-like phenotype associated with cerebral anomalies and severe epilepsy. Pathogenic variants in PIK3CA and PIK3R1, as well as GNAQ and GNA11, were absent in affected cutaneous tissue biopsies. Instead, we identified two somatic pathogenic variants in the AKT3 gene. Subsequent analysis of the DNA obtained from surgically resected brain tissue of one of the two patients confirmed the presence of the AKT3 variant. Focal cortical dysplasia was also detected in this patient. Genetic analysis thus facilitated workup to reach a precise diagnosis for these patients, associating the vascular anomaly with the neurological symptoms. This study underscores the importance of searching for additional signs and symptoms to guide the diagnostic workup, especially in cases with atypical vascular malformations. In addition, it strongly emphasizes the significance of genotype-phenotype correlation studies in guiding clinicians' informed decision-making regarding patient care.

De novo variants in the non-coding spliceosomal snRNA gene RNU4-2 are a frequent cause of syndromic neurodevelopmental disorders

Around 60% of individuals with neurodevelopmental disorders (NDD) remain undiagnosed after comprehensive genetic testing, primarily of protein-coding genes 1 . Increasingly, large genome-sequenced cohorts are improving our ability to discover new diagnoses in the non-coding genome. Here, we identify the non-coding RNA RNU4-2 as a novel syndromic NDD gene. RNU4-2 encodes the U4 small nuclear RNA (snRNA), which is a critical component of the U4/U6.U5 tri-snRNP complex of the major spliceosome 2 . We identify an 18 bp region of RNU4-2 mapping to two structural elements in the U4/U6 snRNA duplex (the T-loop and Stem III) that is severely depleted of variation in the general population, but in which we identify heterozygous variants in 119 individuals with NDD. The vast majority of individuals (77.3%) have the same highly recurrent single base-pair insertion (n.64_65insT). We estimate that variants in this region explain 0.41% of individuals with NDD. We demonstrate that RNU4-2 is highly expressed in the developing human brain, in contrast to its contiguous counterpart RNU4-1 and other U4 homologs, supporting RNU4-2 's role as the primary U4 transcript in the brain. Overall, this work underscores the importance of non-coding genes in rare disorders. It will provide a diagnosis to thousands of individuals with NDD worldwide and pave the way for the development of effective treatments for these individuals.

Impact of newborn screening for fatty acid oxidation disorders on neurological outcome: A Belgian retrospective and multicentric study

Fatty acid oxidation (FAO) disorders are autosomal recessive genetic disorders affecting either the transport or the oxidation of fatty acids. Acute symptoms arise during prolonged fasting, intercurrent infections, or intense physical activity. Metabolic crises are characterized by alteration of consciousness, hypoglycemic coma, hepatomegaly, cardiomegaly, arrhythmias, rhabdomyolysis, and can lead to death. In this retrospective and multicentric study, the data of 54 patients with FAO disorders were collected. Overall, 35 patients (64.8%) were diagnosed after newborn screening (NBS), 17 patients on clinical presentation (31.5%), and two patients after family screening (3.7%). Deficiencies identified included medium-chain acyl-CoA dehydrogenase (MCAD) deficiency (75.9%), very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (11.1%), long-chain hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency (3.7%), mitochondrial trifunctional protein (MTP) deficiency (1.8%), and carnitine palmitoyltransferase 2 (CPT 2) deficiency (7.4%). The NBS results of 25 patients were reviewed and the neurological outcome of this population was compared with that of the patients who were diagnosed on clinical presentation. This article sought to provide a comprehensive overview of how NBS implementation in Southern Belgium has dramatically improved the neurological outcome of patients with FAO disorders by preventing metabolic crises and death. Further investigations are needed to better understand the physiopathology of long-term complications in order to improve the quality of life of patients and to ensure optimal management.

Neurological presentations of inborn errors of purine and pyrimidine metabolism

Purines and pyrimidines are essential components as they are the building blocks of vital molecules, such as nucleic acids, coenzymes, signalling molecules, as well as energy transfer molecules. Purine and pyrimidine metabolism defects are characterised by abnormal concentrations of purines, pyrimidines and/or their metabolites in cells or body fluids. This phenomenon is due to a decreased or an increased activity of enzymes involved in this metabolism and has been reported in humans for over 60 years. This review provides an overview of neurological presentations of inborn errors of purine and pyrimidine metabolism. These conditions can lead to psychomotor retardation, epilepsy, hypotonia, or microcephaly; sensory involvement, such as deafness and visual disturbances; multiple malformations, as well as muscular symptoms. Clinical signs are often nonspecific and thus overlooked, but some diseases are treatable and early diagnosis may improve the child's future. Although these metabolic hereditary diseases are rare, they are most probably under-diagnosed. When confronted with suggestive clinical or laboratory signs, clinicians should prescribe genetic testing in association with a biochemical screening including thorough purine and pyrimidine metabolites analysis and/or specific enzyme evaluation. This is most likely going to increase the number of confirmed patients.

A novel ELOVL4 variant, L168S, causes early childhood-onset Spinocerebellar ataxia-34 and retinal dysfunction: a case report

Spinocerebellar ataxia 34 (SCA34) is an autosomal dominant inherited disease characterized by age-related cerebellar degeneration and ataxia caused by mutations in the Elongation of Very Long Chain Fatty Acid-4 (ELOVL4) gene. The ELOVL4 enzyme catalyzes the biosynthesis of both very long chain saturated fatty acids (VLC-SFA) and very long chain polyunsaturated fatty acids (VLC-PUFA) that are important for neuronal, reproductive, and skin function. Several variants in ELOVL4 have been shown to cause different tissue-specific disorders including SCA34 with or without Erythrokeratodermia Variabilis (EKV), a skin condition characterized by dry, scaly skin, Autosomal Dominant Stargardt-Like Macular Dystrophy (STGD3), and seizures associated with neuro-ichthyotic disorders. What is puzzling is how different mutations in the same gene seem to cause different tissue-specific disorders. To date, no SCA34 patients have presented with both SCA34 and STGD3 pathology that is caused by ELOVL4 variants that cause truncation of ELOVL4. Here, we report a novel case of an early childhood onset and rapidly progressive cerebellar degeneration and retinal dysfunction in a Belgian-Italian girl who developed severe dysarthria and gait problems starting at about 3.5 years of age and progressed to immobility by 4.5 years of age. Brain magnetic resonance imaging (MRI) revealed progressive vermian, cerebellar, cortical atrophy, progressive corpus callosum slimming, and hot cross bun sign visible on the MRI. Ophthalmological examinations also revealed progressive macular dysfunction as measured by electroretinography. Using exome sequencing, we identified a novel heterozygous ELOVL4 variant, c.503 T > C (p. L168S) in the patient. To understand the enzymatic function of this novel ELOVL4 variant and how it alters the levels of VLC-PUFA and VLC-SFA biosynthesis to contribute to cerebellar and retinal dysfunction, we expressed wild-type ELOVL4 or the L168S ELOVL4 variant in cell culture and supplemented the cultures with VLC-PUFA or VLC-SFA precursors. We showed that the L168S ELOVL4 variant is deficient in the biosynthesis of VLC-SFA and VLC-PUFA. Our work suggests that differential depletion of these fatty acids may be a contributing factor to the pathogenic mechanism of SCA34 with or without EKV. Further studies will help further define how the different ELOVL4 variants cause different tissue-specific disorders with variable ages of onset.

De novo variants in CNOT9 cause a neurodevelopmental disorder with or without epilepsy

PURPOSE

The study aimed to clinically and molecularly characterize the neurodevelopmental disorder associated with heterozygous de novo variants in CNOT9.

METHODS

Individuals were clinically examined. Variants were identified using exome or genome sequencing. These variants were evaluated using in silico predictions and their functional relevance was further assessed by molecular models and research in the literature. The variants have been classified according to the criteria of the American College of Medical Genetics (ACMG).

RESULTS

We report on seven individuals carrying de novo missense variants in CNOT9; p.(Arg46Gly), p.(Pro131Leu), p.(Arg227His) and, recurrent in four unrelated individuals, p.(Arg292Trp). All affected persons have DD/ID, with five of them showing seizures. Other symptoms include muscular hypotonia, facial dysmorphism, and behavioral abnormalities. Molecular modeling predicted that the variants are damaging and would lead to reduced protein stability or impaired recognition of interaction partners. Functional analyses in previous studies showed a pathogenic effect of p.(Pro131Leu) and p.(Arg227His).

CONCLUSION

We propose CNOT9 as a novel gene for neurodevelopmental disorder and epilepsy.

Phenotypic spectrum of patients with Poretti-Boltshauser syndrome: Patient report of antenatal ventriculomegaly and esophageal atresia

Poretti-Boltshauser syndrome (PTBHS) is an autosomal recessive disorder characterized by cerebellar dysplasia with cysts and an abnormal shape of the fourth ventricle on neuroimaging, due to pathogenic variants in the LAMA1 gene. The clinical spectrum mainly consists of neurological and ophthalmological manifestations, including non-progressive cerebellar ataxia, oculomotor apraxia, language impairment, intellectual disability, high myopia, abnormal eye movements and retinal dystrophy. We report a patient presenting with ventriculomegaly on antenatal neuroimaging and a neonatal diagnosis of Type III esophageal atresia. She subsequently developed severe myopia and strabismus with retinal dystrophy, mild developmental delay, and cerebellar dysplasia. Genetic investigations confirmed PTBHS. This report confirms previous reports of antenatal ventriculomegaly in PTBHS patients and documents a so far unreported occurrence of esophageal atresia in PTBHS. We additionally gathered phenotype and genotype descriptions of published cases in an effort to better define the spectrum of PTBHS.

Usefulness of serum neurofilament light in the assessment of neurologic outcome in the pediatric population: a systematic literature review

Children undergoing general anesthesia and surgery in the early years of life are exposed to the possible neurotoxicity of anesthetic agents. Prospective studies have shown deficits in behavior, executive function, social communication, and motor function in children undergoing anesthesia and surgery. Different biomarkers of neuronal injury have been evaluated neuronal injury in the pediatric population, among which neurofilaments represent a significant advantage as they are proteins exclusively expressed in neuronal tissue. Our aim was to evaluate the utility of serum neurofilament light (NfL) as a prognostic biomarker of neuronal injury in the pediatric population. A literature search was performed on PubMed, Embase, and Cochrane Databases in November 2022 for studies concerning serum NfL in the pediatric population in addition to a neurological assessment. Inclusion criteria were as follows: (1) prospective or retrospective studies, (2) studies including pediatric population until the age of 18 years, (3) serum NfL sampling, and (4) evaluation of neurological outcome. Data collection regarding study design, pediatric age, serum NfL levels, and results for neurological assessment were extracted from each study. Four manuscripts met the inclusion criteria and evaluated the prognostic utility of serum NfL in neonatal encephalopathy in correlation with the neurodevelopmental outcome that was assessed by the Bayley Scales of Infant Development until the age of 2 years. Children with neonatal encephalopathy showed significantly higher serum NfL vs. healthy controls and high serum NfL levels predicted an adverse neurological outcome. The decrease of serum NfL to a nadir point between 10 and 15 years old reflects the brain growth in healthy controls. No studies were available in the perioperative period.  Conclusions: Serum NfL is a valuable biomarker in evaluating neuronal injury in the pediatric population. Further studies with perioperative serial sampling of serum NfL combined with standardized neurodevelopmental tests should be conducted to evaluate the neurotoxicity of anesthetic agents and monitor the effectiveness of specific neuroprotective strategies in pediatric patients undergoing anesthesia and surgery. What is Known: • Preclinical animal data have shown neurotoxicity of the anesthetic agents in the developing brain. • Data regarding anesthetic neurotoxicity in humans show limitations and no objective tools are available. What is New: • This systematic review showed that serum NfL is a valuable biomarker of neuronal injury in the pediatric population. • Perioperative use of serum NfL may be considered in future trials evaluating anesthetic neurotoxicity in the pediatric population and in monitoring neuroprotective strategies.

Influence of early identification and therapy on long-term outcomes in early-onset MTHFR deficiency

MTHFR deficiency is a severe inborn error of metabolism leading to impairment of the remethylation of homocysteine to methionine. Neonatal and early-onset patients mostly exhibit a life-threatening acute neurologic deterioration. Furthermore, data on early-onset patients' long-term outcomes are scarce. The aims of this study were (1) to study and describe the clinical and laboratory parameters of early-onset MTHFR-deficient patients (i.e., ≤3 months of age) and (2) to identify predictive factors for severe neurodevelopmental outcomes in a cohort with early and late onset MTHFR-deficient patients. To this end, we conducted a retrospective, multicentric, international cohort study on 72 patients with MTHFR deficiency from 32 international metabolic centres. Characteristics of the 32 patients with early-onset MTHFR deficiency were described at time of diagnosis and at the last follow-up visit. Logistic regression analysis was used to identify predictive factors of severe neurodevelopmental outcome in a broader set of patients with early and non-early-onset MTHFR deficiency. The majority of early-onset MTHFR-deficient patients (n = 32) exhibited neurologic symptoms (76%) and feeding difficulties (70%) at time of diagnosis. At the last follow-up visit (median follow-up time of 8.1 years), 76% of treated early-onset patients (n = 29) exhibited a severe neurodevelopmental outcome. Among the whole study population of 64 patients, pre-symptomatic diagnosis was independently associated with a significantly better neurodevelopmental outcome (adjusted OR 0.004, [0.002-0.232]; p = 0.003). This study provides evidence for benefits of pre-symptomatic diagnosis and appropriate therapeutic management, highlighting the need for systematic newborn screening for MTHFR deficiency and pre-symptomatic treatment that may improve outcome.

Disorders of purine biosynthesis metabolism

Purines are essential molecules that are components of vital biomolecules, such as nucleic acids, coenzymes, signaling molecules, as well as energy transfer molecules. The de novo biosynthesis pathway starts from phosphoribosylpyrophosphate (PRPP) and eventually leads to the synthesis of inosine monophosphate (IMP) by means of 10 sequential steps catalyzed by six different enzymes, three of which are bi-or tri-functional in nature. IMP is then converted into guanosine monophosphate (GMP) or adenosine monophosphate (AMP), which are further phosphorylated into nucleoside di- or tri-phosphates, such as GDP, GTP, ADP and ATP. This review provides an overview of inborn errors of metabolism pertaining to purine synthesis in humans, including either phosphoribosylpyrophosphate synthetase (PRS) overactivity or deficiency, as well as adenylosuccinate lyase (ADSL), 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC), phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), and adenylosuccinate synthetase (ADSS) deficiencies. ITPase deficiency is being described as well. The clinical spectrum of these disorders is broad, including neurological impairment, such as psychomotor retardation, epilepsy, hypotonia, or microcephaly; sensory involvement, such as deafness and visual disturbances; multiple malformations, as well as muscle presentations or consequences of hyperuricemia, such as gouty arthritis or kidney stones. Clinical signs are often nonspecific and, thus, overlooked. It is to be hoped that this is likely to be gradually overcome by using sensitive biochemical investigations and next-generation sequencing technologies.

Fructose-1,6-bisphosphatase deficiency causes fatty liver disease and requires long-term hepatic follow-up

Liver disease, occurring during pediatric or adult age, is often of undetermined cause. Some cases are probably related to undiagnosed inherited metabolic disorders. Hepatic disorders associated with fructose-1,6-bisphosphatase deficiency, a gluconeogenesis defect, are not reported in the literature. These symptoms are mainly described during acute crises, and many reports do not mention them because hypoglycemia and hyperlactatemia are more frequently in the forefront. Herein, the liver manifestations of 18 patients affected with fructose-1,6-bisphosphatase deficiency are described and the corresponding literature is reviewed. Interestingly, all 18 patients had liver abnormalities either during follow-up (hepatomegaly [n = 8/18], elevation of transaminases [n = 6/15], bright liver [n = 7/11]) or during acute crises (hepatomegaly [n = 10/17], elevation of transaminases [n = 13/16], acute liver failure [n = 6/14], bright liver [n = 4/14]). Initial reports described cases of liver steatosis, when liver biopsy was necessary to confirm the diagnosis by an enzymatic study. There is no clear pathophysiological basis for this fatty liver disease but we postulate that endoplasmic reticulum stress and de novo lipogenesis activation could be key factors, as observed in FBP1 knockout mice. Liver steatosis may expose patients to severe long-term liver complications. As hypoglycemia becomes less frequent with age, most adult patients are no longer monitored by hepatologist. Signs of fructose-1,6-bisphosphatase deficiency may be subtle and can be missed in childhood. We suggest that fructose-1,6-bisphosphatase deficiency should be considered as an etiology of hepatic steatosis, and a liver monitoring protocol should be set up for these patients, during lifelong follow-up.

Impaired catabolism of free oligosaccharides due to MAN2C1 variants causes a neurodevelopmental disorder

Free oligosaccharides (fOSs) are soluble oligosaccharide species generated during N-glycosylation of proteins. Although little is known about fOS metabolism, the recent identification of NGLY1 deficiency, a congenital disorder of deglycosylation (CDDG) caused by loss of function of an enzyme involved in fOS metabolism, has elicited increased interest in fOS processing. The catabolism of fOSs has been linked to the activity of a specific cytosolic mannosidase, MAN2C1, which cleaves α1,2-, α1,3-, and α1,6-mannose residues. In this study, we report the clinical, biochemical, and molecular features of six individuals, including two fetuses, with bi-allelic pathogenic variants in MAN2C1; the individuals are from four different families. These individuals exhibit dysmorphic facial features, congenital anomalies such as tongue hamartoma, variable degrees of intellectual disability, and brain anomalies including polymicrogyria, interhemispheric cysts, hypothalamic hamartoma, callosal anomalies, and hypoplasia of brainstem and cerebellar vermis. Complementation experiments with isogenic MAN2C1-KO HAP1 cells confirm the pathogenicity of three of the identified MAN2C1 variants. We further demonstrate that MAN2C1 variants lead to accumulation and delay in the processing of fOSs in proband-derived cells. These results emphasize the involvement of MAN2C1 in human neurodevelopmental disease and the importance of fOS catabolism.

Chudley-McCullough Syndrome: A Recognizable Clinical Entity Characterized by Deafness and Typical Brain Malformations

Chudley-McCullough syndrome, a rare autosomal recessive disorder due to pathogenic variants in the GPSM2 (G-protein signaling modulator 2) gene, is characterized by early-onset sensorineural deafness and a typical combination of brain malformations, including ventriculomegaly, (partial) agenesis of the corpus callosum, cerebellar dysplasia, arachnoid cysts, frontal subcortical heterotopia, and midline polymicrogyria. When hearing loss is managed early, most patients have minor or no impairment of motor and cognitive development, despite the presence of brain malformations. We report 2 cases of Chudley-McCullough syndrome, one presenting with congenital deafness and normal development except for speech delay and one presenting prenatally with ventriculomegaly and an atypical postnatal course characterized by epileptic spasms, deafness, and moderate intellectual disability. These highlight the challenges faced by clinicians when predicting prognosis based on pre- or postnatal imaging of brain malformations. We have also reviewed the phenotype and genotype of previous published cases to better understand Chudley-McCullough syndrome.

Phenotype description in KIF5C gene hot-spot mutations responsible for malformations of cortical development (MCD)

Malformations of cortical development (MCD) represent a large group of brain cortical anomalies characterized by distinctive MRI findings. This 'radiologically-based' classification required re evaluation over time on identified underlying mechanisms (cytogenetic and/or molecular). The understanding of genotype findings (nature of cytogenetic/molecular mutation, cellular pathways consequences, timing, …) draw line of evidence on these distinctive group of conditions whereas sometimes precise and constant recurrent genotype/phenotype correlation may not be present. The clinical diagnosis of MCD is often difficult due to variability and rarity of individual types of malformations. Recent studies have established a relationship between lissencephaly and pathogenic variants in genes involved in the kinesin/tubulin pathways, as the KIF5C gene. Pathogenic variants in the KIF5C gene are a more recently discovered cause of severe developmental delay with epilepsy, characterized by specific malformation of cortical development such as pachygyria. Only seven children have been described to date. We report the natural history of a sixteen years old patient identified carrier of a KIF5C gene mutation who developed infantile epilepsy. We then gather phenotype description and molecular results of all reported patients so far in order to better define this entity.

A 7-Year-Old Child With Headaches and Prolonged Fever Associated With Oral and Nail Lesions

A 7-year-old child of Turkish origin presented with headache and vomiting in the context of prolonged fever of unknown source. At examination, oral candidiasis and chronic onychomycosis were noted. A Candida meningoencephalitis was diagnosed and intravenous Amphotericin B liposomal was given during 6 months relayed by oral Fluconazole after regression of CNS lesions was observed on MRI. A complete immune evaluation was performed, and genetic analysis detected homozygous CARD9 mutation. CARD9 deficiency have been associated with invasive candidiasis in otherwise healthy patients. Culture of the cerebrospinal fluid grew for multisensitive Candida albicans. Brain magnetic resonance (MRI) showed the presence of focal lesions in the left caudate nucleus and in the right cerebellar hemisphere. Medullar MRI showed diffuse meningeal nodular lesions. Treatment with intravenous amphotericin B liposomal was given during 6 months relayed by oral fluconazole after regression of CNS lesions was observed on MRI. A complete immune evaluation was performed and genetic analysis detected a homozygous CARD9 mutation. CARD9 deficiency have been associated with invasive candidiasis in otherwise healthy patients.

SLC13A3 variants cause acute reversible leukoencephalopathy and α-ketoglutarate accumulation

OBJECTIVE

SLC13A3 encodes the plasma membrane Na⁺ /dicarboxylate cotransporter 3, which imports inside the cell 4 to 6 carbon dicarboxylates as well as N-acetylaspartate (NAA). SLC13A3 is mainly expressed in kidney, in astrocytes, and in the choroid plexus. We describe two unrelated patients presenting with acute, reversible (and recurrent in one) neurological deterioration during a febrile illness. Both patients exhibited a reversible leukoencephalopathy and a urinary excretion of α-ketoglutarate (αKG) that was markedly increased and persisted over time. In one patient, increased concentrations of cerebrospinal fluid NAA and dicarboxylates (including αKG) were observed. Extensive workup was unsuccessful, and a genetic cause was suspected.

METHODS

Whole exome sequencing (WES) was performed. Our teams were connected through GeneMatcher.

RESULTS

WES analysis revealed variants in SLC13A3. A homozygous missense mutation (p.Ala254Asp) was found in the first patient. The second patient was heterozygous for another missense mutation (p.Gly548Ser) and an intronic mutation affecting splicing as demonstrated by reverse transcriptase polymerase chain reaction performed in muscle tissue (c.1016 + 3A > G). Mutations and segregation were confirmed by Sanger sequencing. Functional studies performed on HEK293T cells transiently transfected with wild-type and mutant SLC13A3 indicated that the missense mutations caused a marked reduction in the capacity to transport αKG, succinate, and NAA.

INTERPRETATION

SLC13A3 deficiency causes acute and reversible leukoencephalopathy with marked accumulation of αKG. Urine organic acids (especially αKG and NAA) and SLC13A3 mutations should be screened in patients presenting with unexplained reversible leukoencephalopathy, for which SLC13A3 deficiency is a novel differential diagnosis. ANN NEUROL 2019;85:385-395.

Hydrocephalus in children under the age of five from diagnosis to short-/medium-/long-term progression: a retrospective review of 142 children

The aim of this study is to evaluate the clinical history and prognosis of children with early-onset hydrocephalus. The retrospective study's inclusion criteria were hydrocephalus diagnosis before the age of 5 years, independent of aetiology, and birth details, January 1, 2000 to December 31, 2014. Overall, 142 children were entered into the study, divided into 11 aetiological groups: premature-birth post-intraventricular haemorrhage (16%), brain tumours (16%), spina bifida (15%), aqueductal stenosis (8%), post-meningitis (8%), post-haemorrhage (8%), Dandy-Walker malformation (6%), unknown origin (6%), arachnoid cyst (5%), miscellaneous obstruction (4%), and various causes (8%). In total, 23 patients died, primarily from the tumour group. Ventriculostomy, performed 42 times, was successful in 20 patients. Overall, 226 internal shunts were placed in 99 children. Infectious complications affected 19% of children after shunt placement and 51% after mechanical complications. Mean follow-up was 4 years 10 months, with 61% of children progressing fairly well, especially those with aqueductal stenosis, cysts, and unknown or diverse obstructive causes. Post-meningitis hydrocephalus displayed the poorest outcome. Isolated obstructive hydrocephalus exhibited better prognosis, with most obstructive aetiologies effectively treated via ventriculostomy. Children treated by shunt placement were more at risk of complications. Aetiologies with associated abnormalities and neurological sequelae had poorer outcomes.

Childhood hearing loss is a key feature of CAPOS syndrome: A case report

CAPOS syndrome (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) is a rare neurological disorder, recently associated with the c.2452G > A hotspot mutation in the ATP1A3 gene, with sensorineural hearing loss as a prominent feature. We herein report on a girl who has experienced hearing loss for three years following an initial encephalitic episode when aged 15 months old. CAPOS was diagnosed only when she was six years old by targeted testing whilst she displayed optic atrophy, cerebellar signs and areflexia. CAPOS syndrome should be considered in the differential diagnosis of acquired childhood deafness, prompting clinicians to search for associated neurological features.

Cerebral germinoma revealed through a polydipsic polyuric syndrome in a 10-year-old girl: case report

Cerebral germinoma is rare. Although the imaging of the germinoma is very evocative, it's very polymorphic clinical expression is at the origin of misguided diagnosis, as illustrated in our case. We report the case of a 10-year-old girl with diabetes insipidus evolving for 12 months associated with a decrease in visual acuity. Brain MRI (Magnetic Resonance Imaging) revealed a tumor process in the suprasellar region. The stereotaxic biopsy of the tumor confirmed the diagnosis of the hypothalamic germinoma, which allowed the patient to be treated by radiotherapy and chemotherapy. The incidence of cerebral germinoma, its clinical (principally diabetes insipidus) and radiological features as well as therapeutic strategies are discussed hereby.

Unusual association between lysinuric protein intolerance and moyamoya vasculopathy

INTRODUCTION

Lysinuric protein intolerance (LPI) is a form of inherited aminoaciduria caused by a deficiency in the cationic amino acid transport process on the basolateral membrane of enterocytes and renal tubular cells. Clinical signs include gastrointestinal symptoms, failure to thrive, hepatosplenomegaly, osteoporosis, episodes of coma, intellectual deficiency, lung and renal involvement, bone marrow abnormalities, as well as altered immune response. Moyamoya disease is a cerebrovascular disorder predisposing sufferers to stroke through progressive stenosis of the intracranial internal carotid arteries and their proximal branches. Patients with characteristic moyamoya vasculopathy who also exhibit well-recognized associated conditions, such as Down syndrome or sickle-cell disease, are diagnosed with moyamoya syndrome, whereas those with no known associated risk factors are said to suffer from moyamoya disease.

CASE STUDY

A 5-year-old girl exhibiting aversion to protein-rich food and splenomegaly presented with a history of recurrent ischemic strokes. Cerebral angiography confirmed moyamoya vasculopathy. Metabolic investigation revealed abnormalities characteristic of LPI. This diagnosis was confirmed by the detection of a mutation within the SLC7A7 gene upon molecular investigation.

CONCLUSION

To the best of our knowledge, this is the first reported case of an association between moyamoya vasculopathy and LPI. While the question of association or coincidence cannot yet be answered, several pathophysiological consequences of LPI can be defined as separate, such as links between the impact of low arginine levels on the function of vascular endothelium and brain nitric oxide metabolism, as well as hemophagocytic syndrome associated with the risk of vasculitis, thus accounting for the development of moyamoya vasculopathy.

Neurological improvement following intravenous high-dose folinic acid for cerebral folate transporter deficiency caused by FOLR-1 mutation

BACKGROUND

Cerebral folate transporter deficiency caused by FOLR-1 mutations has been described in 2009. This condition is characterized by a 5MTHF level <5 nmol/l in the CSF, along with regression of acquisition in the second year of life, ataxia, and refractory myoclonic epilepsy. Oral or intravenous folinic acid (5-formyltetrahydrofolate) treatment has been shown to improve clinical status.

CASE PRESENTATION

We present the cases of two sisters with cerebral folate transport deficiency caused by mutation in the folate receptor 1 (FOLR1) gene (MIM *136430). Following recommendations, we administered oral folinic acid at 5 mg/kg/day, resulting in some initial clinical improvement, yet severe epilepsy persisted. During treatment, cerebrospinal fluid (CSF) analysis revealed normal 5-methyltetrahydrofolate (5MTHF) levels (60.1 nmol/l; normal range: 53-182 nmol/l). Epilepsy proved difficult to control and the younger patient exhibited neurological regression. We then administered high-dose folinic acid intravenously over 3 days (6 mg/kg/day for 24 h, then 12 mg/kg/day for 48 h), which significantly improved clinical status and epilepsy. CSF analysis revealed high 5MTHF levels following intravenous infusion (180 nmol/l). Treatment continued with monthly intravenous administrations of 20-25 mg/kg folinic acid. At 2 years post-treatment, clinical improvement was confirmed.

CONCLUSIONS

This report illustrates that cerebral folate transporter deficiency caused by FOLR-1 mutations is a treatable condition and can potentially be cured by folinic acid treatment. As already reported, early effective treatment is known to improve outcomes in affected children. In our study, intravenous high-dose folinic acid infusions appeared to optimize clinical response.

Eight further individuals with intellectual disability and epilepsy carrying bi-allelic CNTNAP2 aberrations allow delineation of the mutational and phenotypic spectrum

BACKGROUND

Heterozygous copy number variants (CNVs) or sequence variants in the contactin-associated protein 2 gene CNTNAP2 have been discussed as risk factors for a wide spectrum of neurodevelopmental and neuropsychiatric disorders. Bi-allelic aberrations in this gene are causative for an autosomal-recessive disorder with epilepsy, severe intellectual disability (ID) and cortical dysplasia (CDFES). As the number of reported individuals is still limited, we aimed at a further characterisation of the full mutational and clinical spectrum.

METHODS

Targeted sequencing, chromosomal microarray analysis or multigene panel sequencing was performed in individuals with severe ID and epilepsy.

RESULTS

We identified homozygous mutations, compound heterozygous CNVs or CNVs and mutations in CNTNAP2 in eight individuals from six unrelated families. All aberrations were inherited from healthy, heterozygous parents and are predicted to be deleterious for protein function. Epilepsy occurred in all affected individuals with onset in the first 3.5 years of life. Further common aspects were ID (severe in 6/8), regression of speech development (5/8) and behavioural anomalies (7/8). Interestingly, cognitive impairment in one of two affected brothers was, in comparison, relatively mild with good speech and simple writing abilities. Cortical dysplasia that was previously reported in CDFES was not present in MRIs of six individuals and only suspected in one.

CONCLUSIONS

By identifying novel homozygous or compound heterozygous, deleterious CNVs and mutations in eight individuals from six unrelated families with moderate-to-severe ID, early onset epilepsy and behavioural anomalies, we considerably broaden the mutational and clinical spectrum associated with bi-allelic aberrations in CNTNAP2.

Evidence of a wide spectrum of cardiac involvement due to ACAD9 mutations: Report on nine patients

Acyl-CoA dehydrogenase 9 (ACAD9) is a mitochondrial protein involved in oxidative phosphorylation complex I biogenesis. This protein also exhibits acyl-CoA dehydrogenase (ACAD) activity. ACAD9-mutated patients have been reported to suffer from primarily heart, muscle, liver, and nervous system disorders. ACAD9 mutation is suspected in cases of elevated lactic acid levels combined with complex I deficiency, and confirmed by ACAD9 gene analysis. At least 18 ACAD9-mutated patients have previously been reported, usually displaying severe cardiac involvement. We retrospectively studied nine additional patients from three unrelated families with a wide spectrum of cardiac involvement between the families as well as the patients from the same families. All patients exhibited elevated lactate levels. Deleterious ACAD9 mutations were identified in all patients except one for whom it was not possible to recover DNA. To our knowledge, this is one of the first reports on isolated mild ventricular hypertrophy due to ACAD9 mutation in a family with moderate symptoms during adolescence. This report also confirms that dilated cardiomyopathy may occur in conjunction with ACAD9 mutation and that some patients may respond clinically to riboflavin treatment. Of note, several patients suffered from patent ductus arteriosus (PDA), with one exhibiting a complex congenital heart defect. It is yet unknown whether these cardiac manifestations were related to ACAD9 mutation. In conclusion, this disorder should be suspected in the presence of lactic acidosis, complex I deficiency, and any cardiac involvement, even mild.

Two novel EIF2S3 mutations associated with syndromic intellectual disability with severe microcephaly, growth retardation, and epilepsy

X-chromosome exome sequencing was performed to identify the genetic cause of syndromic intellectual disability in two unrelated families with suspected X-linked inheritance. In both families, affected males presented with severe intellectual disability, microcephaly, growth retardation, and epilepsy. A missense mutation (c.777T>G p.(Ile259Met)) and a frameshift mutation (c.1394_1397del p.(Ile465Serfs*4)) were identified in the EIF2S3 gene in the hemizygous state in affected patients, and in the heterozygous states female obligate carriers. A missense mutation in EIF2S3, coding for the gamma-subunit of the translation initiation factor eIF2, was reported once in a family presenting with similar clinical features. Morpholino-based knockdown of the zebrafish EIF2S3 ortholog (eif2s3) recapitulates the human microcephaly and short stature phenotype, supporting the pathogenicity of the identified variants. Our data confirm that EIF2S3 mutation is implicated in a rare, but recognizable, form of syndromic intellectual disability. © 2016 Wiley Periodicals, Inc.

CCDC115 Deficiency Causes a Disorder of Golgi Homeostasis with Abnormal Protein Glycosylation

Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the underlying cell-biological processes in the Golgi. Therefore, uncovering genetic defects and annotating gene function are challenging. Exome sequencing in a family with three siblings affected by abnormal Golgi glycosylation revealed a homozygous missense mutation, c.92T>C (p.Leu31Ser), in coiled-coil domain containing 115 (CCDC115), the function of which is unknown. The same mutation was identified in three unrelated families, and in one family it was compound heterozygous in combination with a heterozygous deletion of CCDC115. An additional homozygous missense mutation, c.31G>T (p.Asp11Tyr), was found in a family with two affected siblings. All individuals displayed a storage-disease-like phenotype involving hepatosplenomegaly, which regressed with age, highly elevated bone-derived alkaline phosphatase, elevated aminotransferases, and elevated cholesterol, in combination with abnormal copper metabolism and neurological symptoms. Two individuals died of liver failure, and one individual was successfully treated by liver transplantation. Abnormal N- and mucin type O-glycosylation was found on serum proteins, and reduced metabolic labeling of sialic acids was found in fibroblasts, which was restored after complementation with wild-type CCDC115. PSI-BLAST homology detection revealed reciprocal homology with Vma22p, the yeast V-ATPase assembly factor located in the endoplasmic reticulum (ER). Human CCDC115 mainly localized to the ERGIC and to COPI vesicles, but not to the ER. These data, in combination with the phenotypic spectrum, which is distinct from that associated with defects in V-ATPase core subunits, suggest a more general role for CCDC115 in Golgi trafficking. Our study reveals CCDC115 deficiency as a disorder of Golgi homeostasis that can be readily identified via screening for abnormal glycosylation in plasma.

Inherited CARD9 deficiency in otherwise healthy children and adults with Candida species-induced meningoencephalitis, colitis, or both

BACKGROUND

Invasive infections of the central nervous system (CNS) or digestive tract caused by commensal fungi of the genus Candida are rare and life-threatening. The known risk factors include acquired and inherited immunodeficiencies, with patients often displaying a history of multiple infections. Cases of meningoencephalitis, colitis, or both caused by Candida species remain unexplained.

OBJECTIVE

We studied 5 previously healthy children and adults with unexplained invasive disease of the CNS, digestive tract, or both caused by Candida species. The patients were aged 39, 7, 17, 37, and 26 years at the time of infection and were unrelated, but each was born to consanguineous parents of Turkish (2 patients), Iranian, Moroccan, or Pakistani origin. Meningoencephalitis was reported in 3 patients, meningoencephalitis associated with colitis was reported in a fourth patient, and the fifth patient had colitis only.

METHODS

Inherited caspase recruitment domain family, member 9 (CARD9) deficiency was recently reported in otherwise healthy patients with other forms of severe disease caused by Candida, Trichophyton, Phialophora, and Exophiala species, including meningoencephalitis but not colitis caused by Candida and Exophiala species. Therefore we sequenced CARD9 in the 5 patients.

RESULTS

All patients were found to be homozygous for rare and deleterious mutant CARD9 alleles: R70W and Q289* for the 3 patients with Candida albicans-induced meningoencephalitis, R35Q for the patient with meningoencephalitis and colitis caused by Candida glabrata, and Q295* for the patient with Candida albicans-induced colitis. Regardless of their levels of mutant CARD9 protein, the patients' monocyte-derived dendritic cells responded poorly to CARD9-dependent fungal agonists (curdlan, heat-killed C albicans, Saccharomyces cerevisiae, and Exophiala dermatitidis).

CONCLUSION

Invasive infections of the CNS or digestive tract caused by Candida species in previously healthy children and even adults might be caused by inherited CARD9 deficiency.

Spontaneous improvement in oculomotor function of children with cerebral palsy

Eye movements are essential to get a clear vision of moving objects. In the present study, we assessed quantitatively the oculomotor deficits of children with cerebral palsy (CP). We recorded eye movements of 51 children with cerebral palsy (aged 5-16 years) with relatively mild motor impairment and compared their performance with age-matched control and premature children. Overall eye movements of children with CP are unexpectedly close to those of controls even though some oculomotor parameters are biased by the side of hemiplegia. Importantly, the difference in performance between children with CP and controls decreases with age, demonstrating that the oculomotor function of children with CP develops as fast as or even faster than controls for some visual tracking parameters. That is, oculomotor function spontaneously improves over the course of childhood. This evolution highlights the ability of lesioned brain of children with CP to compensate for impaired motor function beyond what would be achieved by normal development on its own.

Uncommon Leber "plus" disease associated with mitochondrial mutation m.11778G>A in a premature child

Leber hereditary optic neuropathy is a well-known mitochondrial disorder that leads to bilateral subacute visual failure. Although visual impairment is often the sole clinical feature, additional and severe neurologic abnormalities also have been documented for this disease. We report on a 13-year-old boy who has presented with severe visual failure since early childhood in a context of prematurity. In the first years of his life, clinical features included delayed psychomotor development and ataxia. The clinical presentation, which was initially attributed to prematurity, worsened thereafter, and the child developed acute neurologic degradation with the typical radiological findings of Leigh syndrome. The mitochondrial DNA point mutation 11778G>A was identified in the ND4 gene. The probable influence of environmental background on clinical expression of Leber optic neuropathy, particularly those of prematurity and oxygen therapy, is discussed in our manuscript.

MAN1B1 deficiency: an unexpected CDG-II

Congenital disorders of glycosylation (CDG) are a group of rare metabolic diseases, due to impaired protein and lipid glycosylation. In the present study, exome sequencing was used to identify MAN1B1 as the culprit gene in an unsolved CDG-II patient. Subsequently, 6 additional cases with MAN1B1-CDG were found. All individuals presented slight facial dysmorphism, psychomotor retardation and truncal obesity. Generally, MAN1B1 is believed to be an ER resident alpha-1,2-mannosidase acting as a key factor in glycoprotein quality control by targeting misfolded proteins for ER-associated degradation (ERAD). However, recent studies indicated a Golgi localization of the endogenous MAN1B1, suggesting a more complex role for MAN1B1 in quality control. We were able to confirm that MAN1B1 is indeed localized to the Golgi complex instead of the ER. Furthermore, we observed an altered Golgi morphology in all patients' cells, with marked dilatation and fragmentation. We hypothesize that part of the phenotype is associated to this Golgi disruption. In conclusion, we linked mutations in MAN1B1 to a Golgi glycosylation disorder. Additionally, our results support the recent findings on MAN1B1 localization. However, more work is needed to pinpoint the exact function of MAN1B1 in glycoprotein quality control, and to understand the pathophysiology of its deficiency.

Glycosylation concerns the synthesis of sugar chains, their addition onto proteins and/or lipids, and their subsequent modifications. The resulting glycoproteins serve many critical roles in metabolism. The importance of this pathway is illustrated by a group of diseases called Congenital Disorders of Glycosylation (CDG). To date, over 60 distinct disorders have been described. In the present study, we demonstrated that mutations in MAN1B1, a gene formerly linked to non-syndromic intellectual disability, cause CDG. We described 7 patients with similar clinical features (developmental delay, intellectual disability, facial dysmorphism and obesity), defining MAN1B1-CDG as a syndrome. Furthermore, we confirmed that the MAN1B1 protein is localized into the Golgi apparatus instead of the endoplasmic reticulum, where it was assumed to reside for many years. Moreover, we showed that mutations in MAN1B1 lead to alterations of the Golgi structure.

The saccadic system does not compensate for the immaturity of the smooth pursuit system during visual tracking in children

Motor skills improve with age from childhood into adulthood, and this improvement is reflected in the performance of smooth pursuit eye movements. In contrast, the saccadic system becomes mature earlier than the smooth pursuit system. Therefore, the present study investigates whether the early mature saccadic system compensates for the lower pursuit performance during childhood. To answer this question, horizontal eye movements were recorded in 58 children (ages 5-16 yr) and 16 adults (ages 23-36 yr) in a task that required the combination of smooth pursuit and saccadic eye movements. Smooth pursuit performance improved with age. However, children had larger average position error during target tracking compared with adults, but they did not execute more saccades to compensate for their low pursuit performance despite the early maturity of their saccadic system. This absence of error correction suggests that children have a lower sensitivity to visual errors compared with adults. This reduced sensitivity might stem from poor internal models and longer processing time in young children.

Metabolic diagnostic work-up in chronic conditions

Neurological symptoms are very frequent in inborn errors of metabolism. This chapter presents a general approach to investigate inborn errors of metabolism in chronic neurological conditions. A diagnostic work-up has been designed to evaluate progressive neurological conditions with motor, cognitive, and/or behavioral signs in early infancy, late infancy to early childhood, and late childhood to adolescence. Inborn errors of metabolism associated with peripheral neuropathies, microcephaly, or macrocephaly are also reviewed.

Tyrosinemia Type III detected via neonatal screening: management and outcome

Tyrosinemia Type III is caused by the deficiency of 4-hydroxyphenylpyruvate dioxygenase (4-HPPD), an enzyme involved in the catabolic pathway of tyrosine. To our knowledge, only a few patients presenting with this disease have been described in the literature, and the clinical phenotype remains variable and unclear. We report the case of a boy with tyrosinemia Type III detected using neonatal screening, who is homozygous for the splice donor mutation IVS11+1G>A in intron 11 of the HPD gene. At the age of 30 months, the boy's outcome under mild protein restriction was characterized by normal growth and psychomotor development.

Pandemic A/H1N1v influenza 2009 in hospitalized children: a multicenter Belgian survey

Background

During the 2009 influenza A/H1N1v pandemic, children were identified as a specific "at risk" group. We conducted a multicentric study to describe pattern of influenza A/H1N1v infection among hospitalized children in Brussels, Belgium.

Methods

From July 1, 2009, to January 31, 2010, we collected epidemiological and clinical data of all proven (positive H1N1v PCR) and probable (positive influenza A antigen or culture) pediatric cases of influenza A/H1N1v infections, hospitalized in four tertiary centers.

Results

During the epidemic period, an excess of 18% of pediatric outpatients and emergency department visits was registered. 215 children were hospitalized with proven/probable influenza A/H1N1v infection. Median age was 31 months. 47% had ≥ 1 comorbid conditions. Febrile respiratory illness was the most common presentation. 36% presented with initial gastrointestinal symptoms and 10% with neurological manifestations. 34% had pneumonia. Only 24% of the patients received oseltamivir but 57% received antibiotics. 10% of children were admitted to PICU, seven of whom with ARDS. Case fatality-rate was 5/215 (2%), concerning only children suffering from chronic neurological disorders. Children over 2 years of age showed a higher propensity to be admitted to PICU (16% vs 1%, p = 0.002) and a higher mortality rate (4% vs 0%, p = 0.06). Infants less than 3 months old showed a milder course of infection, with few respiratory and neurological complications.

Conclusion

Although influenza A/H1N1v infections were generally self-limited, pediatric burden of disease was significant. Compared to other countries experiencing different health care systems, our Belgian cohort was younger and received less frequently antiviral therapy; disease course and mortality were however similar.

Cardiac and neurological assessment of normothermia/warm blood cardioplegia vs hypothermia/cold crystalloid cardioplegia in pediatric cardiac surgery: insight from a prospective randomized trial

OBJECTIVE

Although normothermia and warm blood cardioplegia are widely used in adults, cold crystalloids and hypothermia remain routinely used in pediatric cardiac surgery. The superiority of either technique in both brain and myocardial protection remains controversial. We designed a prospective randomized study to compare both approaches in terms of early myocardial protection and late neurodevelopmental status.

METHODS

From 2004 to 2005, 47 patients were randomly assigned to either mild hypothermia associated to cold crystalloid cardioplegia (CCC, 22 patients) or normothermia with intermittent warm blood cardioplegia (IWBC, 25 patients). Intramyocyte adenosine triphosphate (ATP) was measured before, during and after cardioplegic arrest and results between groups were compared. In addition to their cardiac status, early and late neurologic assessment was performed by psychometric evaluation tests.

RESULTS

Intracellular ATP levels were not significantly different between the two groups. However, intragroup comparison revealed different profiles according to myocardial protection: in the normothermia/warm blood cardioplegia group, ATP concentration increased during cardioplegic arrest and returned to initial values afterward (11 nmol mg(-1) vs 21 nmol mg(-1) vs 10 nmol mg(-1), p < 0.001), such changes did not occur in the cold protocol (17 nmol mg(-1) vs 19 nmol mg(-1) vs 14 nmol mg(-1), p = NS). Early neurological outcome was similar in both groups. At late follow-up (mean = 4 years), no significant difference was observed between the two groups.

CONCLUSIONS

This study demonstrates that normothermia/IWBC protocols are not deleterious when compared with more conventional approaches. A more physiologic ATP steady state, reflecting the absence of cellular ischemic insult was observed in the IWBC group. Importantly, no significant difference was found between IWBC and CCC groups in terms of early and late neurodevelopmental status.

Neural correlates of symbolic number comparison in developmental dyscalculia

Developmental dyscalculia (DD) is a deficit in number processing and arithmetic that affects 3-6% of schoolchildren. The goal of the present study was to analyze cerebral bases of DD related to symbolic number processing. Children with DD aged 9-11 years and matched children with no learning disability history were investigated using fMRI. The two groups of children were controlled for general cognitive factors, such as working memory, reading abilities, or IQ. Brain activations were measured during a number comparison task on pairs of Arabic numerals and a color comparison task on pairs of nonnumerical symbols. In each task, pairs of stimuli that were close or far on the relevant dimension were constituted. Brain activation in bilateral intraparietal sulcus (IPS) was modulated by numerical distance in controls but not in children with DD. Moreover, although the right IPS responded to numerical distance only, the left IPS was influenced by both numerical and color distances in control children. Our findings suggest that dyscalculia is associated with impairment in areas involved in number magnitude processing and, to a lesser extent, in areas dedicated to domain-general magnitude processing.

Meningitis with subdural empyema due to non-typhoid Salmonella in a 9-month-old girl

We report a case of a 9-month-old baby admitted to the hospital because of low-grade fever, focal seizures in a context of watery diarrhea for 14 days' duration. The patient workup revealed a mild neutrophilic pleocytosis on cerebrospinal fluid (46 cells/microl), a positive stool culture for Salmonella pomona sensitive to ceftriaxone and ciprofloxacin, and a subdural empyema (SDE) on the cerebral MRI. The child received an intravenous third-generation cephalosporin for 4 weeks which resulted in cure. This case highlights an unusual extra-intestinal complication of non-typhoid salmonella infection. Involvement of the central nervous system with non-typhoidal salmonellosis is an important complication that can result in significant morbidity if not recognized and treated promptly. A focal intra-cranial infection must be considered in the differential diagnosis of any child presenting with focal seizures and gastroenteritis due to Salmonella. Appropriate diagnostic imaging of the head (cerebral CT scan with contrast and/or MRI) is mandatory to exclude the presence of an intra-cranial complication, even in the presence of negative CSF culture for Salmonella. Subfrontal and subtemporal SDE are sometimes missed on axial CT scans and better appreciated on MRI. Non-surgical treatment of small subdural empyemas with prolonged intravenous antibiotic therapy is a therapeutic option.

A Novel Splicing Mutation in SLC12A3 Associated With Gitelman Syndrome and Idiopathic Intracranial Hypertension

We report a case of Gitelman syndrome (GS) in a dizygotic twin who presented at 12 years of age with growth delay, metabolic alkalosis, hypomagnesemia and hypokalemia with inappropriate kaliuresis, and idiopathic intracranial hypertension with bilateral papilledema (pseudotumor cerebri). The patient, her twin sister, and her mother also presented with cerebral cavernous malformations. Based on the early onset and normocalciuria, Bartter syndrome was diagnosed first. However, mutation analysis showed that the proband is a compound heterozygote for 2 mutations in SLC12A3: a substitution of serine by leucine at amino acid position 555 (p.Ser555Leu) and a novel guanine to cytosine transition at the 5' splice site of intron 22 (c.2633+1G>C), providing the molecular diagnosis of GS. These mutations were not detected in 200 normal chromosomes and cosegregated within the family. Analysis of complementary DNA showed that the heterozygous nucleotide change c.2633+1G>C caused the appearance of 2 RNA molecules, 1 normal transcript and 1 skipping the entire exon 22 (r.2521_2634del). Supplementation with potassium and magnesium improved clinical symptoms and resulted in catch-up growth, but vision remained impaired. Three similar associations of Bartter syndrome/GS with pseudotumor cerebri were found in the literature, suggesting that electrolyte abnormalities and secondary aldosteronism may have a role in idiopathic intracranial hypertension. This study provides further evidence for the phenotypical heterogeneity of GS and its association with severe manifestations in children. It also shows the independent segregation of familial cavernomatosis and GS.

Sustained engraftment and tissue enzyme activity after liver cell transplantation for argininosuccinate lyase deficiency

BACKGROUND & AIMS

Donor cell engraftment with expression of enzyme activity is the goal of liver cell transplantation for inborn errors of liver metabolism with a view to achieving sustained metabolic control.

METHODS

Sequential hepatic cell transplantations using male and female cells were performed in a 3.5-year-old girl with argininosuccinate lyase deficiency over a period of 5 months. Beside clinical, psychomotor, and metabolic follow-up, engraftment was analyzed in repeated liver biopsies (2.5, 5, 8, and 12 months after first infusion) by fluorescence in situ hybridization for the Y-chromosome and by measurement of tissue enzyme activity.

RESULTS

Metabolic control was achieved together with psychomotor catch-up, changing the clinical phenotype from a severe neonatal one to a moderate late-onset type. The child was no longer hospitalized and was able to attend normal school. Sustained engraftment of male donor liver cells was shown in repeated biopsies, reaching 19% at 8 months and 12.5% at the 12-month follow-up. XXYY tetraploid donor cells were mainly detected during the infusion period (2.5- and 5-month biopsies), whereas in the follow-up 8-month and 1-year biopsies, diploid donor cell subpopulations had become dominant. Moreover, argininosuccinate lyase activity, originally absent, became measurable in 2 different biopsy samples at 8 months, reaching 3% of control activity, indicating in situ metabolic effect and supporting the clinical evolution to a moderate form of the disease.

CONCLUSIONS

Liver cell transplantation can achieve donor cell engraftment in humans in a significant proportion, leading to sustained metabolic and clinical control with psychomotor catch-up.

Levetiracetam in a neonate with malignant migrating partial seizures

This report describes the first neonatal case of "malignant migrating partial seizures in infancy" with a positive therapeutic response to levetiracetam. This patient is the youngest reported infant with this rare syndrome, and the report provides the first documentation on levetiracetam treatment in a neonatal patient. Treatment with levetiracetam improved both ictal and interictal status. This observation also highlights the need to consider and include malignant migrating partial seizures in the differential diagnosis of early neonatal seizure disorders, even during the first hours of life.

Long-term follow-up of neonatal mitochondrial cytopathies: a study of 57 patients

OBJECTIVES

We sought to determine the long-term clinical and biochemical outcome of newborns with mitochondrial cytopathies (MCs) and to identify possible prognostic factors that may modify the course of these diseases.

MATERIAL AND METHODS

Fifty-seven newborns with MCs were identified in a retrospective review (1983-2002). We defined 2 different outcome categories: clinical (neurologic, hepatic, myopathic, and multiorganic) and biochemical (lactate level normalization or initially normal remaining unchanged, decreased but not normalized, and persistently high). We used 2 different statistical approaches: (1) survival studies depending on the initial symptoms and lactate and enzymatic deficiencies using the Kaplan-Meier method; and (2) the same variables compared with different survival age groups and clinical and biochemical outcome categories using the chi2 test.

RESULTS

Thirty-three patients died (57.8%), 12 remain alive (21%), and 12 were lost in the follow-up; 6 of them are currently older than 4 years. Most of the patients manifested multiorganic disease (64.8%) and high lactate level (77.1%) over time. Children surviving to 2.5 to 3 years of age were more likely to survive for a long period of time. Initial neurologic and hepatic presentation increased the risk to develop neurologic disease and severe persistent hyperlactacidemia, respectively. Initial severe hyperlactacidemia and combined enzyme deficiencies were significant risk factors for higher mortality and multiorganic disorders. Two patients with exclusively myopathic outcome are alive and cognitively normal at 12 years of life.

CONCLUSIONS

Children with neonatal-onset MCs have very high mortality and poor prospects. However, some with life-threatening presentations may gradually improve, giving rise to less severe diseases. Those with exclusively myopathic symptoms have a better prognosis.

Delta1-pyrroline-5-carboxylate synthase deficiency: neurodegeneration, cataracts and connective tissue manifestations combined with hyperammonaemia and reduced ornithine, citrulline, arginine and proline

Delta1-pyrroline-5-carboxylate synthase (P5CS) catalyses the reduction of glutamate to Delta1-pyrroline-5-carboxylate, a critical step in the biosynthesis of proline, ornithine and arginine. Recently, we reported a newly recognised inborn error due to deficiency of P5CS in two sibs, one presenting at birth with hypotonia, dysmorphic signs, pes planus and clonic seizures. Both developed progressive neurodegeneration and peripheral neuropathy, joint laxity, skin hyperelasticity and bilateral subcapsular cataracts. Their metabolic phenotype includes mild hyperammonaemia, hypo-ornithinaemia, hypocitrullinaemia, hypo-argininaemia and hypoprolinaemia. Incorporation of 3H-proline into protein was deficient in fibroblasts incubated with 3H-glutamate. Both patients are homozygous for the missense mutation R84Q in P5CS. Here, we describe the clinical phenotype of the sibs in detail and show that a relative deficiency of urea cycle intermediates (ornithine, citrulline and arginine) during fasting periods results in a paradoxical hyperammonaemia. Furthermore, we show the results of ornithine loading tests and indirect enzyme studies corroborating the biological significance of the defect in P5CS in vivo.

CONCLUSION

The metabolic phenotype of Delta1-pyrroline-5-carboxylate synthase deficiency is easily missed. The combination of low levels of ornithine, citrulline, arginine and proline plus a tendency to hyperammonaemia or one of the above together with a clinical phenotype of neurodegeneration with peripheral neuropathy and/or cataracts and connective tissue manifestations should suggest this disorder. Early recognition would allow a therapeutic trial with citrulline and proline.