ALG1-CDG: Clinical and Molecular Characterization of 39 Unreported Patients.

Congenital disorders of glycosylation (CDG) arise from pathogenic mutations in over 100 genes leading to impaired protein or lipid glycosylation. ALG1 encodes a ß1,4 mannosyltransferase that catalyzes the addition of the first of nine mannose moieties to form a dolichol-lipid linked oligosaccharide intermediate required for proper N-linked glycosylation. ALG1 mutations cause a rare autosomal recessive disorder termed ALG1-CDG. To date 13 mutations in 18 patients from 14 families have been described with varying degrees of clinical severity. We identified and characterized 39 previously unreported cases of ALG1-CDG from 32 families and add 26 new mutations. Pathogenicity of each mutation was confirmed based on its inability to rescue impaired growth or hypoglycosylation of a standard biomarker in an alg1-deficient yeast strain. Using this approach we could not establish a rank order comparison of biomarker glycosylation and patient phenotype, but we identified mutations with a lethal outcome in the first two years of life. The recently identified protein-linked xeno-tetrasaccharide biomarker, NeuAc-Gal-GlcNAc2 , was seen in all 27 patients tested. Our study triples the number of known patients and expands the molecular and clinical correlates of this disorder.

New hyperekplexia mutations provide insight into glycine receptor assembly, trafficking, and activation mechanisms.

Hyperekplexia is a syndrome of readily provoked startle responses, alongside episodic and generalized hypertonia, that presents within the first month of life. Inhibitory glycine receptors are pentameric ligand-gated ion channels with a definitive and clinically well stratified linkage to hyperekplexia. Most hyperekplexia cases are caused by mutations in the α1 subunit of the human glycine receptor (hGlyR) gene (GLRA1). Here we analyzed 68 new unrelated hyperekplexia probands for GLRA1 mutations and identified 19 mutations, of which 9 were novel. Electrophysiological analysis demonstrated that the dominant mutations p.Q226E, p.V280M, and p.R414H induced spontaneous channel activity, indicating that this is a recurring mechanism in hGlyR pathophysiology. p.Q226E, at the top of TM1, most likely induced tonic activation via an enhanced electrostatic attraction to p.R271 at the top of TM2, suggesting a structural mechanism for channel activation. Receptors incorporating p.P230S (which is heterozygous with p.R65W) desensitized much faster than wild type receptors and represent a new TM1 site capable of modulating desensitization. The recessive mutations p.R72C, p.R218W, p.L291P, p.D388A, and p.E375X precluded cell surface expression unless co-expressed with α1 wild type subunits. The recessive p.E375X mutation resulted in subunit truncation upstream of the TM4 domain. Surprisingly, on the basis of three independent assays, we were able to infer that p.E375X truncated subunits are incorporated into functional hGlyRs together with unmutated α1 or α1 plus ß subunits. These aberrant receptors exhibit significantly reduced glycine sensitivity. To our knowledge, this is the first suggestion that subunits lacking TM4 domains might be incorporated into functional pentameric ligand-gated ion channel receptors.

Novel mutations consolidate KCTD7 as a progressive myoclonus epilepsy gene.

BACKGROUND: The progressive myoclonus epilepsies (PMEs) comprise a group of clinically and genetically heterogeneous disorders characterised by myoclonus, epilepsy, and neurological deterioration. This study aimed to identify the underlying gene(s) in childhood onset PME patients with unknown molecular genetic background. METHODS: Homozygosity mapping was applied on genome-wide single nucleotide polymorphism data of 18 Turkish patients. The potassium channel tetramerisation domain-containing 7 (KCTD7) gene, previously associated with PME in a single inbred family, was screened for mutations. The spatiotemporal expression of KCTD7 was assessed in cellular cultures and mouse brain tissue. RESULTS: Overlapping homozygosity in 8/18 patients defined a 1.5 Mb segment on 7q11.21 as the major candidate locus. Screening of the positional candidate gene KCTD7 revealed homozygous missense mutations in two of the eight cases. Screening of KCTD7 in a further 132 PME patients revealed four additional mutations (two missense, one in-frame deletion, and one frameshift-causing) in five families. Eight patients presented with myoclonus and epilepsy and one with ataxia, the mean age of onset being 19 months. Within 2 years after onset, progressive loss of mental and motor skills ensued leading to severe dementia and motor handicap. KCTD7 showed cytosolic localisation and predominant neuronal expression, with widespread expression throughout the brain. None of three polypeptides carrying patient missense mutations affected the subcellular distribution of KCTD7. DISCUSSION: These data confirm the causality of KCTD7 defects in PME, and imply that KCTD7 mutation screening should be considered in PME patients with onset around 2 years of age followed by rapid mental and motor deterioration.

Chloral hydrate versus hydroxyzine HCL for sedation prior to pediatric sleep EEG recording.

OBJECTIVE: The sleep electroencephalogram (EEG) can reveal certain epileptiform activity patterns and facilitate localization of the focus. Sedation is often required for sleep EEG recording in pediatric patients, but there is no consensus on the optimal sedative. Hydroxyzine HCL (HH) and chloral hydrate (CH) are popular sedatives, but HH is rarely used for pediatric sleep EEG recording. The goal of this prospective study was to compare CH to HH for sleep induction efficacy, safety and effects on pediatric sleep EEG pattern. RESEARCH DESIGN AND METHODS: A total of 282 children (age 4-9 years) referred to our sleep EEG laboratory and requiring sedation were randomly assigned to two groups: the CH Group (n = 141) received 50 mg/kg CH and the HH group (n = 141) received 1 mg/kg HH. If sedation was unsatisfactory, a second equal dose of the same sedative was administered 30 min later. RESULTS: Sleep induction was less successful in the HH group compared to the CH group (p < 0.001). Sleep onset latency was significantly longer in the HH group (p < 0.01) and the proportion of HH group patients requiring a second sedative dose significantly higher (p < 0.01). There was no significant difference in the proportion of patients exhibiting epileptiform activity on the EEG or in adverse event rate between groups. CONCLUSION: CH was a superior sedative compared to HH owing to more rapid and successful sleep induction with no increase in adverse events.

A randomized trial comparing amitriptyline versus topiramate for the prophylaxis of chronic daily headache in pediatric patients.

OBJECTIVE: the goal of this prospective and double-blind study was to compare the efficacy of amitriptyline and topiramate for the prevention of pediatric chronic daily headache (CDH). RESEARCH DESIGN AND METHODS: fifty-seven children (aged 9-16 yr) diagnosed with CDH were randomly assigned to two groups: group A (n = 29 patients) received amitriptyline 0.5 mg/kg/d and group B (n = 28 patients) received topiramate 25 mg/d increasing up to 100 mg/d according to patient response. Treatment response was monitored for at least 4 months. RESULTS: fifty-five percent of the patients in group A responded to amitriptyline and 61% of patients in group B responded to topiramate as defined by a reduction of more than 50% in monthly headache frequency. There was no significant difference in responder rate or adverse event rate between the two groups (p > 0.05). By the end of the 4-month treatment period, there were no significant differences in the final average severity and monthly frequency of headaches between treatment groups. CONCLUSION: these results suggest that the efficacy and tolerability of topiramate is equivalent to that of amitriptyline for reducing the frequency of headache in pediatric CHD patients.

Dual anca positivity in a child with moyamoya-like cerebral vascular changes: an unusual presentation with sudden homonymous hemianopsia.

A 12-year-old girl presented with a sudden decrease in her right visual acuity and homonymous hemianopsia. An angiography of the retinal arteries demonstrated recanalized occlusion of the right retinal artery. Cerebral angiography showed bilateral internal carotid artery stenosis associated with the development of collateral circulation. Laboratory evaluations revealed dual antineutrophil cytoplasmic antibodies (ANCA) positivity [anti-proteinase (anti-PR3) ANCA and anti-myeloperoxidase (anti-MPO) ANCA], anticardiolipin (aCL) antibodies, and low titers of antinuclear antibodies (ANA). There was no evidence of active systemic lupus erythematosus (SLE), ANCA-related vasculitis, or other risk factors for cerebral occlusion, such as antiphospholipid syndrome (APS). Dual positivity for both cytoplasmic (c-ANCA) and perinuclear (p-ANCA) antineutrophil antibodies has been found previously in a small number of reports, but to our knowledge, this case represents the first case of moyamoya disease associated with dual ANCA positivity.

Serum concentrations of neuron-specific enolase in pediatric migraine.

Recent studies suggest that migraine might be a progressive disease that causes neuronal damage, rather than being a benign headache disorder. The objective of the present study was to investigate the concentrations of neuron-specific enolase (NSE) in pediatric migraineurs in order to identify possible neuronal damage. Forty-one children and adolescents with migraine (mean age: 14.58 +/- 2.35 years, range: 7-17 years, 12 with aura) and 30 control subjects were included. Serum NSE levels were measured during the attack and repeated at least 7 days thereafter in the patients, and measurements were obtained once in the control group. There were no significant differences in NSE concentrations with respect to values during the attack versus pain-free period or between the patient and control groups. NSE levels did not differ according to the clinical variables, including the presence of aura, severity and duration of headaches, nor with the length of migraine. In conclusion, our study showed that NSE levels did not change during migraine attack in pediatric patients. Further studies with different markers are warranted to assess possible neuronal injury in pediatric migraine.

Respiratory-chain deficiency presenting as diffuse mesangial sclerosis with NPHS3 mutation.

Renal manifestations of mitochondrial cytopathies have been described, but nephrotic syndrome with respiratory-chain disorders have been described extremely rarely. We report a 9-month-old boy with a mitochondrial cytopathy preceded by a 2-month history of steroid-resistant nephrotic syndrome. Percutaneous renal biopsy revealed diffuse mesangial sclerosis, and mutational analysis was compatible with PLCE1 mutation. However, electron microscopic findings of renal tissue, sensorineural hearing loss, and other ocular and neurologic findings led us to suspect mitochondrial cytopathy. Muscle tissue analysis showed a deficiency of the respiratory chain complex IV. The clinical presentation of our patient is not typical for primary cytochrome oxidase (COX) deficiency but showed similarities with patients carrying AR mutations in COX10. This was the first case in the literature with both PLCE1 mutation and COX deficiency. We could not identify pathogenic mutations in the COX10 gene, suggesting that PLCE1 deficiency could be the cause of the secondary deficiency of COX. Another, more likely, possibility is that the mitochondriopathy phenotype is caused by another mutation homozygous by descent in a yet unidentified recessive gene.

Posterior reversible leukoencephalopathy syndrome in children with hematologic disorders.

OBJECTIVE: Posterior reversible leukoencephalopathy syndrome (PRES) is characterized by headache, altered mental status, cortical blindness, and seizures associated with neuroradiological findings. It involves predominantly white matter of the parieto-occipital lobes. Several medications and disorders play a role in the etiology of PRES. In this study, we aimed to show how the prognosis of PRES in hematological diseases of childhood might be according to the etiological factors. METHODS: Here, we report PRES in six patients, aged 4 to 14 years, with diagnoses of leukemia and aplastic anemia. RESULTS: Suggested causes in our patients were chemotherapeutics, hypertension, infection and antimicrobial drug administration, tumor lysis syndrome, acute renal failure and hemodialysis, immunosuppressive drug administration, and hypomagnesemia. One of the patients died of sepsis, renal failure and pulmonary hemorrhage and another died of relapse after total recovery from PRES. The other four patients are under follow-up without problems. CONCLUSION: We suggest that PRES can recover fully with early diagnosis and treatment whereas it can show poor prognosis depending on the etiology.

Elevated CK-MB mass and plasma brain-type natriuretic peptide concentrations following convulsive seizures in children and adolescents: possible evidence of subtle cardiac dysfunction.

PURPOSE: To evaluate the presence of myocardial injury during convulsive seizures in children and adolescents by determining serum concentrations of cardiac troponin I (cTnI), creatine kinase-MB mass (CK-MB mass), and plasma brain-type natriuretic peptide (BNP). METHODS: Thirty-one children (20 boys; mean age, 6.6 +/- 5.34 years) with convulsive seizures and 50 healthy children were enrolled. Serum cTnI, CK-MB mass, and plasma BNP concentrations were analyzed 12 h after the seizure and repeated 7 days thereafter in the patient group and obtained one time in the control group. RESULTS: The difference between serum concentrations of cTnI obtained 12 h and 7 days after the seizure was not statistically significant. cTnI levels 12 h postictal and those in control subjects also were not significantly different. CK-MB mass and BNP at the 12th h were higher than those obtained on the 7th day (p < 0.05 and p < 0.001, respectively). Children with seizures had increased levels of CK-MB mass and BNP 12 h after seizure than control subjects (p < 0.05 and p < 0.001, respectively). The results of electrocardiography (ECG) recordings, which were obtained up to 30 min after seizure activity, were completely normal in patients with seizure. CONCLUSION: Normal cTnI levels are not indicative of overt myocardial necrosis in patients with seizures. However, markedly elevated BNP concentrations together with elevated CK-MB mass levels do suggest subtle cardiac dysfunction in patients with seizure, and further large-scale studies are warranted.

The use of levetiracetam in a child with nonconvulsive status epilepticus.

Levetiracetam is an antiepileptic drug that was shown to be effective in various seizure types. Experience with this agent for treating status epilepticus is just emerging. To the best of our knowledge, there is no report in the literature regarding its use in children with nonconvulsive status epilepticus. We here report a liver-transplanted child with nonconvulsive status epilepticus who responded well to oral levetiracetam treatment.

Neurologic complications of liver transplantation in pediatric patients with the hepatic form of Wilson's disease.

The literature contains very little documentation on neurologic complications in liver transplant recipients for Wilson's disease. We retrospectively reviewed 17 consecutive cases of pediatric liver transplantation for the hepatic form of Wilson's disease to assess the types of neurologic complications that occurred, the incidence of those problems, and associated factors in this patient group. The patients were 12 boys and 5 girls; indications for liver transplantation were fulminant hepatic failure in 3 patients and chronic hepatic failure in 14 patients. Neurologic complications were observed in 10 of the 17 patients as 16 episodes. The most common neurologic complications were seizure (7 episodes in 6 patients) and sudden-onset headache (5 episodes in 4 patients). Tacrolimus was identified as the only possible cause of headache in 3 episodes. Encephalitis was the cause in 1 and intracranial hemorrhage was the cause in the other headache episode. We also noted 1 episode of tremor, 1 episode of acute dystonic reaction, 1 episode of diffuse encephalopathy, and 1 episode of common peroneal nerve palsy. Immunosuppressive agents were the primary cause of 12 of the 16 episodes of neurologic complications. Uremia with hypertension, compression of the right common peroneal nerve, encephalitis, and intracranial hemorrhages attributable to coagulopathy caused 1 neurologic episode each. Neurologic complications in patients with the hepatic form of Wilson's disease were frequent during the first 30 days after pediatric liver transplantation but did not affect survival. Transplantation teams should be aware of the high incidence of neurologic complications in pediatric patients with the hepatic form of Wilson's disease.

Posterior leukoencephalopathy syndrome in children and adolescents.

Posterior leukoencephalopathy syndrome is a recently identified clinical and radiologic entity. The characteristic radiologic findings are bilateral gray and white matter edema in the posterior regions of the cerebral hemispheres. This article reports clinical and radiologic findings in 10 consecutive episodes of posterior leukoencephalopathy syndrome that were diagnosed in 9 children and adolescents. The causes were immunosuppressive therapy in 7 patients and a combination of renal failure and hypertension in 3. The most common presenting symptoms were seizure and altered consciousness; others included headache, sixth nerve palsy, and cortical blindness. Imaging demonstrated abnormalities in the parietal and occipital lobes in all 10 episodes. The signs and symptoms resolved after immunosuppressive agents were reduced or discontinued, or after uremia and hypertension were corrected. Four patients underwent follow-up cranial imaging, and the images showed nearly complete or complete resolution. The syndrome was clinically reversible in all patients.

Neuroimaging findings in infantile GM1 gangliosidosis.

GM1 gangliosidosis is an autosomal recessive glycosphingolipid storage disease caused by defects in the enzyme beta-galactosidase. Three clinical forms (infantile-, juvenile-, and adult-onset) of the disease are recognized. Patients with infantile GM1 gangliosidosis present at birth or shortly thereafter with somatic and bony changes, followed by severe neurological deterioration ultimately leading to death within the first 2 years of life. We present the brain CT, MRI and MR spectroscopy (MRS) findings in a 17-month-old Turkish girl with infantile GM1 gangliosidosis. Neuroimaging findings in patients with infantile GM1 gangliosidosis have been reported only in a few cases. In this study, MRS of the thalamus was performed to study the metabolic changes in GM1 gangliosidosis. We showed a a decreased NAA/Cr ration and an increased Cho/Cr ratio. To our knowledge, this is the first report of magnetic resonance spectroscopy findings in type-1 GM1 gangliosidosis.

+H-proton-magnetic resonance spectroscopic findings in a patient with acute hemicerebellitis presenting without localized signs: a case report.

Acute cerebellitis (AC) is an inflammatory process involving the cerebellum. Usually, this pathology is bilateral; it is unusual to have a unilateral cerebellitis. Only seven cases of hemicerebellitis have been reported in the literature. Here, we review the literature and report the magnetic resonance imaging (MRI) and proton-magnetic resonance spectroscopic (+H-MRS) findings of a case of acute hemicerebellitis in a 15-year-old girl presenting with 15 days' history of headache.

Refractory status epilepticus owing to human parvovirus B19 encephalitis in a child.

Human parvovirus B19 is the agent that causes erythema infectiosum (fifth disease), a disease that is generally benign and self-limiting. This virus also is associated with severe disease in hemolytic or immunocompromised patients. It rarely causes meningoencephalitis in healthy children. Herein we present the case of a 10-year-old healthy girl with refractory status epilepticus possibly owing to human parvovirus B19 encephalitis who was successfully treated with high-dose corticosteroids. To our knowledge, this is the first report of human parvovirus B19 encephalitis complicated by refractory status epilepticus in a child.

Should we routinely perform blood tests in children with uncontrolled seizures?

The value of biochemical tests in treating patients with uncontrolled seizures is unclear. We present the case of an 8-year-old boy with uncontrolled seizures receiving two antiepileptic drugs. He had been diagnosed with recurrent herpes encephalitis and treated with acyclovir 1 year previously. Laboratory blood analyses, performed because of his uncontrolled seizure episodes, revealed hypocalcemia. Hypoparathyroidism was detected with elevated levels of phosphorus and low levels of parathormone. In conclusion, blood tests, especially to measure calcium, in children with uncontrolled seizures are suggested. Hypoparathyroidism causing hypocalcemia, as present here, is not a rare occurrence.

Vertigo in childhood: a clinical experience.

OBJECTIVE: Vertigo in childhood is a complaint consisting of a wide spectrum of diagnoses. The aim of this study was to evaluate pediatric patients with vertigo with normal eardrum and middle ear findings and discuss the differential diagnoses. METHODS: Patient records of 50 children under 18 years of age with vertigo as the chief complaint, examined at the Baskent University, Research and Application Centers at Konya and Adana otorhinolaryngology clinics between May 2003 and October 2005 were retrospectively reviewed. The questionnaires, laboratory tests including blood samples, audiological and vestibular tests, and final diagnoses were analyzed. Patients with perforated eardrums, otitis media with effusion, and acute upper respiratory tract infections were not included in the study. RESULTS: The study group consisted of 50 patients (33 females, 66%; 17 males, 34%), between 4 and 17 years of age (mean age, 11.5+/-3.9 years). Severe sensorineural hearing loss was present in one patient unilaterally (2%) and one patient bilaterally (2%). Bilateral low-frequency sensorineural hearing loss was present in one patient (2%). Electronystagmography revealed central vestibular abnormalities in three patients (6%). Canal paresis was established in six patients (12%). The Dix-Hallpike test was positive in six patients (12%). The most frequent cause of vertigo was migraine, occurring in 34% of patients (n=17). Other less-frequent etiologies of vertigo were benign paroxysmal vertigo (n=6; 12%), benign paroxysmal positional vertigo (n=6; 12%), psychogenic vertigo (n=5; 10%), epilepsy (n=3; 6%), metabolic disorders (n=3; 6%), vestibular neuritis (n=2; 4%), Meniere's disease (n=1; 2%), perilymphatic fistula (n=1; 2%), amblyopia (n=1; 2%), and unclassifiable (n=5; 10%). CONCLUSIONS: Migraine was found to be the most frequent presenting diagnosis in childhood vertigo, although several peripheral vestibular disorders also were diagnosed. Evaluation of vertigo in childhood should begin with a thorough neuro-otologic evaluation and include other relevant multidisciplinary team members as needed to avoid unnecessary effort and cost.

Is Celiac Disease an Etiological Factor in Children with Nonsyndromic Intellectual Disability?

To determine the prevalence of celiac disease in children and adolescents with nonsyndromic intellectual disability, we investigated serum levels of tissue transglutaminase antibody and total IgA from 232 children with nonsyndromic intellectual disability and in a healthy control group of 239 children. Study participants who were positive for tissue transglutaminase antibody underwent a duodenal biopsy. A total of 3 patients in the nonsyndromic intellectual disability group (5.45%) and 1 in the control group (0.41%) had positive serum tissue transglutaminase antibody (P > .05). Duodenal biopsy confirmed celiac disease in only 1 patient who had nonsyndromic intellectual disability. In this present study, children with nonsyndromic intellectual disability did not exhibit a higher celiac disease prevalence rate compared with healthy controls. Therefore, we suggest that screening test for celiac disease should not be necessary as a part of the management of mild and moderate nonsyndromic intellectual disability. However, cases of severe nonsyndromic intellectual disability could be examined for celiac disease.